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INTERNET DRAFT February 8, 1995 Expires inHTML Working Group T. Berners-Lee INTERNET-DRAFT MIT/W3C <draft-ietf-html-spec-02.txt> D. Connolly Expires: In six monthsHyperTextMay 6, 1995 Hypertext Markup LanguageSpecification- 2.0<draft-ietf-html-spec-01.txt> STATUS OF THIS MEMOCONTENTS 1. Introduction 2. HTML as an Application of SGML 3. HTML as an Internet Media Type 4. Document Structure Elements 5. Character Content 6. Data Elements 7. Character Format Elements 8. Hyperlink Elements 9. Block Structuring Elements 10. Form-based Input Elements 11. HTML Public Text 12. Glossary 13. Bibliography 14. Appendices 15. Acknowledgments Status of this Memo This document is anInternet draft. Internet draftsInternet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents asInternet drafts. Internet draftsInternet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to useInternet draftsInternet-Drafts as reference material or to cite them other than as"work``work inprogress."progress.'' To learn the current status of any Internet-Draft, please check the"1id-abstracts.txt"1id-abstracts.txt listing contained in theInternet- DraftsInternet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Distribution of this document is unlimited. Please send comments to the HTML working group (HTML-WG) of the Internet Engineering Task Force (IETF) at<html- wg@oclc.org>.<html-wg@oclc.org>. Discussions of the group are archived atURL: http://www.acl.lanl.gov/HTML_WG/archives.html. Abstract<URL:http://www.acl.lanl.gov/HTML_WG/archives.html>. ABSTRACT TheHyperTextHypertext Markup Language (HTML) is a simple markup language used to create hypertext documents that areportable from oneplatformto another.independent. HTML documents are SGML documents with generic semantics that are appropriate for representing information from a wide range ofapplications.domains. HTML markup can represent hypertext news, mail, documentation, and hypermedia; menus of options; database query results; simple structured documents with in-lined graphics; and hypertext views of existing bodies of information. HTML has been in use by the World Wide Web (WWW) global information initiative since 1990. This specification roughly corresponds to the capabilities of HTML inBerners-Lee, Connolly, et. al. Page 1 HTML 2.0 February 8, 1995common use prior to June 1994.ItHTML isdefined asan application of ISO Standard 8879:1986 Information Processing Text and Office Systems; Standard Generalized Markup Language (SGML). The"text/html; version=2.0"`"text/html; version=2.0"' Internet Media Type (RFC 1590) and MIME Content Type (RFC 1521) is defined by this specification.Contents Overview1. Introduction The HyperText Markup Language (HTML) is a simple data format used to create hypertext documents that are portable from one platform to another. HTML documents are SGML documents with generic semantics that are appropriate for representing information from a wide range of domains. 1.1. Scope HTMLSpecification........................ 2has been in use by the World-Wide Web (WWW) global information initiative since 1990. This specification corresponds to the capabilities of HTMLSpecification.................................... 11 Security Considerations............................... 52 Obsoletein common use prior to June 1994 andProposed Features........................ 53referred to as ``HTML 2.0''. HTMLDocument Type Definitions........................ 56 Glossary.............................................. 74 References............................................ 77 Acknowledgments....................................... 78 Author's Addresses.................................... 80 1. Overviewis an application of ISO Standard 8879:1986 _Information Processing Text and Office Systems; Standard Generalized Markup Language_ (SGML). The HTMLSpecification This chapterDocument Type Definition (DTD) is asummaryformal definition of the HTMLspecification. See Section 2. for the complete specification.syntax in terms of SGML. This specification also defines HTMLdescribes the structureas an Internet Media Type[IMEDIA] andorganization of a document. It only suggests appropriate presentationsMIME Content Type[MIME] called `text/html', or `text/html; version=2.0'. As such, it defines the semantics of thedocument when processed. InHTMLdocuments, tags define the startsyntax andendhow that syntax should be interpreted by user agents. 1.2. Conformance This specification governs the syntax ofheadings, paragraphs, lists, character highlightingHTML documents andlinks. Mostthe behaviour of HTMLelements are identified in auser agents. 1.2.1. Documents A documentas a start tag, which gives the element name and attributes, followed by the content, followed by the end tag. Start tags are delimited by < and >, and end tags are delimited by </ and >. Example: Berners-Lee, Connolly, et. al. Page 2 HTML 2.0 February 8, 1995 <H1>Thisis aheading</H1> Every HTML document starts with aconforming HTML documentidentifier which contains two sections,only if: * It is aheadconforming SGML document, anda body. The head contains HTML elements which describeit conforms to thedocuments title, usage and relationship with other documents. The body contains otherHTMLelements withDTD (see 11.1, "HTML DTD") * It conforms to theentire text and graphics ofapplication conventions in this specification. For example, thedocument. This overview briefly describesvalue of thesyntax`HREF' attribute ofHTML elementsthe <A> element must conform to the URI syntax. * Its document character set includes ISO-8859-1 andprovides an example HTML document. NOTE: The term "HTML user agent"agrees with ISO10646; that is, each code position listed in 14.1, "The ISO-8859-1 Coded Character Set" isusedincluded, and each code position inthisthe document character set is mapped todescribe applicationsthe same character as ISO10646 designates for thatare used with HTML documents. 1.1 HTML Elements 1.1.1 Document Structure Elements HTML Identifier <HTML> ... </HTML>code position. NOTE - TheHTML identifier defines thedocumentas containingcharacter set is somewhat independent of the character encoding scheme used to represent a document. For example, the ISO-2022-JP character encoding scheme can be used for HTMLelements. It contains onlydocuments, since its repertoire is a subset of theHead and Body elements. Head <HEAD> ... </HEAD>ISO10646 repertoire. TheHead element contains HTML elementscrititcal distinction is thatdescribe the documents title, usage and relationshipnumeric character references agree withother documents. Body <BODY> ... </BODY> The Body element contains the text and its associated HTML elementsISO10646 regardless of how thedocument. Exampledocument is encoded. NOTE - There are a number ofDocument Structure Elements <HTML> <HEAD> <TITLE>The Document's Title</TITLE> </HEAD> <BODY> Berners-Lee, Connolly, et. al. Page 3syntactic idioms that are not supported or are supported inconsistently in some historical user agent implementations. These idioms are called out in notes like this throughout this specification. HTML2.0 February 8, 1995documents should not contain these idioms, at least until such time as support for them is widely deployed. Thedocument's text. </BODY> 1.1.2 Anchor Element Anchor <A> ... </A> An anchor specifiesHTML DTD defines alink to another location (<A HREF>) orstandard HTML document type and several variations, based on feature test entities: HTML.Recommended Certain features of thevalue to use when linking to this location from another location (<A NAME>): See <A HREF="http://www.hal.com/">HaL</A>'s information for more details. <A NAME="B">Section B</A> describes... ... See <A HREF="#B">Section B</A>language are necessary formore information. 1.1.3 Block Formatting Elements Address <ADDRESS> ... </ADDRESS> <ADDRESS> Newsletter editor<BR> J.R. Brown<BR> JimquickPost News, Jumquick, CT 01234<BR> Tel (123) 456 7890 </ADDRESS> Body <BODY> ... </BODY> Place the <BODY> and </BODY> tags above and belowcompatibility with widespread usage, but they may compromise thebodystructural integrity of a document. This feature test entity enables a more prescriptive document type definition that eliminates those features. For example, in order to preserve thetext (not including the head)structure ofyoura document, an editing user agent may translate HTMLdocument. Blockquote <BLOCKQUOTE>... </BLOCKQUOTE> I thinkdocuments to the recommended subset, or itends <BLOCKQUOTE> <P>Soft you now,may require that thefair Ophelia. Nymph, in thy orisons,documents beall my sins remembered. </BLOCKQUOTE> Berners-Lee, Connolly, et. al. Page 4 HTML 2.0 February 8, 1995 but I am not sure. Head <HEAD> ... </HEAD> Every HTML document must have a head, which provides a title. Example: <HTML> <HEAD> <TITLE>Introduction to HTML</TITLE> </HEAD> Headings <H1>This is a first level heading</H1> <P>Therein the recommended subset for import. HTML.Deprecated Certain features of the language aresix levelsnecessary for compatibility with earlier versions ofheadings. <H2>Second level heading</H2> <P>This text appears underthesecond level heading Horizontal Rule <HR> Insertsspecification, but they tend to be used an implemented inconsistently, and their use is deprecated. This feature test entity enables ahorizontal ruledocument type definition thatspanseliminates these features. Documents generated by tranlation software or editing software should not contain these idioms. 1.2.2. User Agents An HTML user agent conforms to this specification if: * It parses thewidthcharacters ofthe document. Example: <HR> <ADDRESS>February 8, 1995, CERN</ADDRESS> </BODY> HTML Identifier <HTML> ... </HTML> Anan HTML documentbegins with an <HTML> taginto data characters andends withmarkup as per [SGML]. * It supports the</HTML> tag. Line Break <BR> Forces a line break: Name<BR> Street address<BR> City, State Zip Paragraph Berners-Lee, Connolly, et. al. Page 5 HTML 2.0 February 8, 1995 <P> ... </P> <H1>This Heading PrecedesISO-8859-1 character encoding scheme, and processes each character in theParagraph</H1> <P>This isISO Latin Alphabet Nr. 1 as specified in 5.1, "The ISO Latin 1 Character Repertoire". NOTE - To support non-western writing systems, HTML user agents should support thetextUnicode-1-1-UTF-8 and Unicode-1-1-UCS-2 encodings and as much of thefirst paragraph. <P>This is the textcharacter repertoire of ISO10646 as is possible as well. * It behaves identically for documents whose parsed token sequences are identical. For example, comments and thesecond paragraph. Although youwhitespace in tags disappear during tokenization, and hence they do notneed to start paragraphs on new lines, maintaining this convention facilitates document maintenance. <P>This isinfluence thetext of a third paragraph. Preformatted Text <PRE> ... </PRE> <PRE WIDTH="80"> This is an examplebehaviour ofpreformatted text. </PRE> Title <TITLE> ... </TITLE> <TITLE>Title of document</TITLE> 1.1.4 List Elements Definition List <DL> ... <DT>term<DD>definition... </DL> <DL> <DT>Term<DD>This is the first definition. <DT>Term<DD>This is the second definition. </DL> Directory List <DIR> ... <LI>List item... </DIR> <DIR> <LI>A-H<LI>I-M <LI>M-R<LI>S-Z </DIR> Menu List <MENU> ... <LI>List item... </MENU> <MENU> Berners-Lee, Connolly, et. al. Page 6 HTML 2.0 February 8, 1995 <LI>First item in the list. <LI>Second item in the list. <LI>Third item in the list. </MENU> Ordered List <OL> ... <LI>List item... </OL> <OL> <LI>Clickconforming user agents. * It allows theWeb buttonuser toopen the Open the URL window. <LI>Enter the URL numbertraverse (or at least attempt to traverse, resources permitting) all hyperlinks in an HTML document. * It allows thetextuser to express all form fieldof the Open URL window. The Web document youvalues specifiedis displayed. <LI>Click highlighted text to move from one linkin an HTML document and toanother. </OL> Unordered List <UL> ... <LI>List item... </UL> <UL> <LI>This is(attempt to) submit thefirst item invalues as requests to information services. NOTE - In thelist. <LI>Thisinterest of robustness and extensibility, there are a number of widely deployed conventions for handling non-conforming documents. See 3.2.1, "Undeclared Markup Error Handling" for details. 2. HTML as an Application of SGML HTML isthe second item in the list. <LI>Thisan application of ISO Standard 8879:1986 - Standard Generalized Markup Language (SGML). SGML is a system for defining structured document types and markup languages to represent instances of those document types[SGML]. The public text -- DTD and SGML declaration -- of thethird itemHTML document type definition are provided in 11, "HTML Public Text". The term _HTML_ refers to both thelist. </UL> 1.1.5 Information Typedocument type defined here andCharacter Formatting Elements Bold <B> ... </B> Suggeststherenderingmarkup language for representing instances ofthe text in boldface. If boldfacethis document type. 2.1. SGML Documents An HTML document isnot available, alternative mapping is allowed. Citation <CITE> ... </CITE> Specifies a citation; typically rendered as italic. Code <CODE> ... </CODE> Indicatesaninline exampleSGML document; that is, a sequence ofcode; typically renderedcharacters organized physically into a set of entities, and logically asmonospaced.. Do not confuse witha hierarchy of elements. The first production of the<PRE> tag. Berners-Lee, Connolly, et. al. Page 7 HTML 2.0 February 8, 1995 Emphasis <EM> ... </EM> Provides typographic emphasis; typically rendered as italics. Italics <I> ... </I> SuggestsSGML grammar separates an SGML document into three parts: an SGML declaration, a prologue, and an instance. For therenderingpurposes oftext in italic font, or slanted if italicthis specification, the prologue isnot available. Keyboard <KBD> ... </KBD> Indicates text typed by a user; typically rendered as monospaced. Sample <SAMP> ... </SAMP> Indicatesasequence of literal characters; typically rendered as monospaced.. Strong <STRONG> ... </STRONG> Provides strong typographic emphasis; typically rendered as bold. Typetype <TT> ... </TT> Specifies thatDTD. This DTD describes another grammar: thetext be renderedstart symbol is given infixed-width font. Variable <VAR> ... </VAR> Indicates a variable name; typically rendered as italic. 1.1.6 Image Element Berners-Lee, Connolly, et. al. Page 8 HTML 2.0 February 8, 1995 Image <IMG> Insertsthereferenced graphic image intodoctype declaration; thedocument atterminals are data characters and tags, and thelocation whereproductions are determined by the elementoccurs. Example: <IMG SRC ="triangle.gif" ALT="Warning:"> Be sure to read these instructions. 1.1.7 Form Elements Form <FORM> ... </FORM>declarations. TheForm element contains nested elements (described below) which define user input controls and allow descriptive textinstance must conform to the DTD, that is, it must bedisplayed whenin thedocument is processed. Input <INPUT> Takes these attributes: ALIGN, MAXLENGTH, NAME, SIZE, SRC, TYPE, VALUE.language defined by this grammar. Thetype attribute can define these field types: CHECKBOX, HIDDEN, IMAGE, PASSWORD, RADIO, RESET, SUBMIT, TEXT. Example: <FORM METHOD="POST" action="http://www.hal.com/sample"> <P>Your name: <INPUT NAME="name" SIZE="48"> <P>Male <INPUT NAME="gender" TYPE=RADIO VALUE="male"> <P>Female <INPUT NAME="gender" TYPE=RADIO VALUE="female"> </FORM> Option <OPTION> The Option element can only occur within a Select element. It represents one choice. Select Berners-Lee, Connolly, et. al. Page 9 HTML 2.0 February 8, 1995 <SELECT NAME="..." > ... </SELECT> Select provides a list of choices. <SELECT NAME="flavor"> <OPTION>Vanilla <OPTION>Strawberry <OPTION>Rum and Raisin <OPTION>Peach and Orange </SELECT> Textarea <TEXTAREA> ... </TEXTAREA> Textarea defines a multi-line text entry input control. It containsSGML declaration determines theinitial text contentslexicon of thecontrol. <TEXTAREA NAME="address" ROWS=64 COLS=6> HaL Computer Systems 1314 Dell Avenue Campbell California 95008 </TEXTAREA> 1.1.8 Character Data in HTML Representing Graphic Characters in HTML Because ofgrammar. It specifies theway specialdocument character set, which determines a character repertoire that contains all charactersare usedthat occur in all text entities inmarking up HTML text, character strings are used to representtheless than (<) and greater than (>) symbolsdocument, and theampersand (&) as shown in Section 2.17.1. Representing Special Characters in HTML HTML inherits both fromcode positions associated with those characters. The SGMLand from MIME in its descriptiondeclaration also specifies the syntax-reference character set ofcharactersthe document, andcharacter sets. The result isasmall amount of duplicationfew other parameters that bind the abstract syntax offunction: there are multiple waysSGML tocodea concrete syntax. This concrete syntax determines how the sequence of characters of the document is mapped to a sequence of terminals inHTML. HTML documents are encoded in some character encoding;thecharacter encoding may be specified, forgrammar of the prologue. For example,byconsider the"charset" parameter associated withfollowing document: <!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN"> <title>Parsing Example</title> <p>Some text. <em>*wow*</em></p> An HTML user agent should use the"text/html" media type. Independent ofSGML declaration is given in 11.2, "SGML Declaration for HTML". According to the document characterencoding used, HTML also allows referencesset there,`*' refers toany ofan asterisk character. The instance above is regarded as theISO Latin-1 alphabet, usingfollowing sequence of terminals: 1. TITLE start-tag 2. data characters: ``Parsing Example'' 3. TITLE end-tag 4. P start-tag 5. data characters ``Some text. '' 6. EM start-tag 7. ``*wow*'' 8. EM end-tag The start symbol of thenamesDTD grammar is HTML, and the productions are given in thetable ISO Latin-1 Character Representations, which is derived from ISO Standard 8879:1986//ENTITIES Added Latin 1//EN. For Berners-Lee, Connolly, et. al. Page 10public text identified by `-//IETF//DTD HTML2.0 February 8, 1995 details, see 2.17.2. 1.2 Example2.0//EN' (11.1, "HTML DTD"). Hence the terminals above parse as: HTMLDocument <HTML> <HEAD> <TITLE>Structural Example</TITLE> </HEAD> <BODY> <H1>First Header</H1> <P>This is| \-HEAD | | | \-TITLE | | | \-<TITLE> | | | \-"Parsing Example" | | | \-</TITLE> | \-BODY | \-P | \-<P> | \-"Some text. " | \-EM | | | \-<EM> | | | \-"*wow*" | | | \-</EM> | \-</P> 2.2. HTML Lexical Syntax SGML specifies an abstract syntax and aparagraph inreference concrete syntax. Aside from certain quantities and capacities (e.g. theexamplelimit on the length of a name), all HTMLfile. Keep in mind thatdocuments use thetitle does not appearreference concrete syntax. In particular, all markup characters are in thedocument text, but that the header (defined by H1) does. <UL> <LI>First item in an unordered list. <LI>Second item in an unordered list. </UL> <P>This is an additional paragraph. Technically, end tags are not required for paragraphs, although theyISO-646-IRV character repertoire. Data characters areallowed. You can includedrawn from the document characterhighlighting in a paragraph. <I>This sentenceset (see 5, "Character Content"). A complete discussion of SGML parsing, e.g. theparagraphmapping of a sequence of characters to a sequence of tags and data isin italics.</I> <IMG SRC ="triangle.gif" alt="Warning:"> Be sureleft toread these instructions. </BODY> </HTML> 2. HTML Specification HTML has been in use bytheWorld Wide Web (WWW) global information initiative since 1990.SGML standard[SGML]. Thisspecification correspondssection is only a summary. 2.2.1. Data Characters Any sequence of characters that do not constitute markup (see 9.6 ``Delimiter Recognition'' of [SGML]) are mapped directly to strings of data characters. Some markup also maps to data character strings. Numeric character references also map to single-character strings, via thelegitimate capabilitiesdocument character set. Each reference to one ofHTMLthe general entities defined incommon use priorthe HTML DTD also maps toJune 1994. Ita single-character string. For example, abc<def => "abc","<","def" abc<def => "abc","<","def" Note that the terminating semicolon isdefinedonly necessary when the character following the reference would otherwise be recognized as markup: abc < def => "abc ","<"," def" abc < def => "abc ","<"," def" And note that anapplication of ISO Standard 8879:1986: Standard Generalized Markup Language (SGML). This specificationampersand isproposedonly recognized asthe Internet Media Type (RFC 1590) and MIME Content Type (RFC 1521) called "text/html",markup when it is followed by a letter or"text/html; version=2.0". This specification also includes: - 5.1 SGML Declarationdigit: abc & lt def => "abc & lt def" abc & 60 def => "abc & 60 def" A useful technique for translating plain text to HTML is to replace each '<', '&', and '>' by an entity reference or numeric character reference as follows: ENTITY NUMERIC CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION & & & Ampersand < < < Less than > > > Greater than NOTE -5.1.1 SampleThere are SGMLOpen Style Entity Catalog for HTML - 5.2 HTML DTD This specification is currently available on the World Wide Web at URL: http://www.hal.com/%7Econnolly/html-spec Berners-Lee, Connolly, et. al. Page 11 HTML 2.0 February 8, 1995 Please send commentsmechanisms, CDATA and RCDATA, to allow most `<', `>', and `&' characters to be entered without thediscussion list at: html- wg@oclc.org 2.1 Levels of Conformance Version 2.0use oftheentity references. Because these features tend to be used and implemented inconsistently, and because they conflict with techinques for reducing HTMLspecification introduces formsto 7 bit ASCII foruser inputtransport, they are not used in this version ofinformation, and adds a distinction between levels of conformance: Level 0 Indicates the minimum conformance level. When writing Level 0 documents, authors can be confident thattherendering at different sites will reflect their intent. Level 1 Includes Level 0 features plus featuresHTML DTD. 2.2.2. Tags Tags delimit elements such as headings, paragraphs, lists, character highlighting andimages. Level 2 Includes all Level 0 and Level 1 features, plus forms. Features of higher levels, suchlinks. Most HTML elements are identified in a document astables, figures,a start-tag, which gives the element name andmathematical formulae,attributes, followed by the content, followed by the end tag. Start-tags areunder discussiondelimited by `<' and `>'; end tags aredescribed as proposed where mentioned. 2.2 Undefined Tagdelimited by `</' andAttribute Names`>'. Anaccepted networking principleexample is: <H1>This is a Heading</H1> Some elements only have a start-tag without an end-tag. For example, tobe conservative in that which one produces, and liberal in that which one accepts. HTML user agents should be liberal except when verifying code. HTML generators should generate strictly conforming HTML. The behaviorcreate a line break, you use the `<BR>' tag. Additionally, the end tags ofHTML user agents reading HTML documentssome other elements, such as Paragraph (`</P>'), List Item (`</LI>'), Definition Term (`</DT>'), anddiscovering tag or attribute names which they do not understand shouldDefinition Description (`<DD>') elements, may beto behave as though, in the case of a tag, the whole tag had not been there but itsomitted. The contenthad, or in the caseof anattribute, that the attribute had not been present. 2.3 Deprecatedelement is a sequence of data character strings andRecommended Sections in DTDs In Section 5., optional "deprecated"nested elements. Some elements, such as anchors, cannot be nested. Anchors and"recommended" sections are used. Conformance with this specification is defined with these sections disabled. Incharacter highlighting may be put inside other constructs. See theliberal spirit of Section 2.2,HTMLuser agents reading HTML documents should accept syntax corresponding to the Berners-Lee, Connolly, et. al. Page 12 HTML 2.0 February 8, 1995 specification with "deprecated" turned on. HTML user agents generatingDTD, 11.1, "HTML DTD" for full details. NOTE - The SGML declaration for HTMLmay in the spirit of conservation, generate documentsspecifies SHORTTAG YES, which means thatconform to the specification with the "recommended" sections turned on. 2.4 HTMLthere are other valid syntaxes for tags, such asan Internet Media Type This (and upward compatible specifications) define the Internet Media Type (RFC 1590)NET tags, `<EM/.../'; empty start tags, `<>'; andMIME Content Type (RFC 1521) called "text/html". The type "text/html" accepts the following parameters: Level The level parameter specifies the feature set used in the document. The levelempty end-tags, `</>'. Until support for these idioms isan integer number, implying that any featureswidely deployed, their use is strongly discouraged. 2.2.3. Names A name consists ofsamea letter followed by up to 71 letters, digits, periods, orlower level may be present in the document. Levels 0, 1hyphens. Element names are not case sensitive, but entity names are. For example, `<BLOCKQUOTE>', `<BlockQuote>', and2`<blockquote>' aredefined by this specification. Version To help avoid future compatibility problems, the version parameter may be used to give the version number of the specification to whichequivalent, whereas `&' is different from `&'. In a start-tag, thedocument conforms. The version number appears atelement name must immediately follow thefront of this documenttag open delimiter `<'. 2.2.4. Attributes In a start-tag, white space andwithinattributes are allowed between thepublic identifier forelement name and theSGML DTD. This specification defines version 2.0. Charset The charset parameter (as defined in section 7.1.1closing delimiter. An attribute typically consists ofRFC 1521)an attribute name, an equal sign, and a value, though some attributes may beused with the text/html to specify the encoding used to represent the HTML document as a sequence of bytes. Normally, text/* media types specifyjust adefaultvalue. White space is allowed around the equal sign. The value ofUS-ASCII forthecharset parameter. However, for text/html, ifattribute may be either: * A string literal, delimited by single quotes or double quotes and not containing any occurrences of thebyte stream contains data thatdelimiting character. * A name token (a sequence of letters, digits, periods, or hyphens) In this example, img isnot inthe7-bit US-ASCII set,element name, `src' is theHTML interpreting agent should assume a default charset of ISO-8859-1. When an HTML documentattribute name, and `http://host/dir/file.gif' isencoded using US-ASCII,themechanismsattribute value: <img src="http://host/dir/file.gif"> NOTE - Some historical implementations consider any occurrence ofnumeric character references (see Section 2.16.2) andthe `>' characterentity references (see Section 2.16.3) may be usedtoencode additional characters from ISO-8859-1. Other values forsignal thecharset parameter are not definedend of a tag. For ompatibility with such implementations, when `>' appears inthis specification, but mayan attribute value, it should bespecified in future Berners-Lee, Connolly, et. al. Page 13 HTML 2.0 February 8, 1995 levels or versions of HTML. It is envisioned that HTML will use the charset parameter to allow support for non-Latin charactersrepresented with a numeric character reference, such asGreek, Arabic, Hebrew, Japanese, rather than relying on any SGML mechanismin: `<IMG SRC="eq1.jpg" alt="a>b">'. A useful technique fordoing so. 2.5 Understanding HTML and SGML HTML iscomputing anapplication of ISO Standard 8879:1986 - Standard Generalized Markup Language (SGML). SGML is a system for defining structured document types, and markup languages to represent instances of those document types. The SGML declarationattribute value literal forHTML isa givenin Section 5.1. Itstring isimplicit among HTML user agents. If the HTML specificationto replace each quote andSGML standard conflict,space character by an entity reference or numeric character reference as follows: ENTITY NUMERIC CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION TAB 	 Tab LF Line Feed CR Carriage Return   Space " " " Quotation mark & & & Ampersand For example: <IMG SRC="image.jpg" alt="First "real" example"> NOTE - Some historical implementations allow any character except space or `>' in a name token. Attributes values must be quoted only if they don't satisfy theSGML standard is definitive. Every SGML document has three parts: SGML declaration Binds SGML processing quantities andsyntaxtoken names to specific values. For example,for a name token. Note that the SGML declaration in section 13.3 limits the length of an attribute value to 1024 characters. Attributes such as ISMAP and COMPACT, may be written using a minimized syntax. The markup: <UL COMPACT="compact"> can be written using a minimized syntax: <UL COMPACT> NOTE - Some historical implementations only understand the minimized syntax. 2.2.5. Comments To include comments in an HTMLDTD specifiesdocument that will be eliminated in thestring that opens an end tag is </mapping to terminals, surround them with `<!--' and `-->'. After themaximum lengthcomment delimiter, all text up to the next occurrence ofa name`-->' is72 characters. Prologue Includes one or more document type declarations, which specifyignored. Hence comments cannot be nested. White space is allowed between theelement types, element relationshipsclosing `--' andattributes. Instance Contains`>', but not between thedataopening `<!' andmarkup of the document.`--'. For example: <HEAD> <TITLE>HTML Guide: Recommended Usage</TITLE> <!-- $Id: html-sgml.sgm,v 1.4 1995/05/06 01:44:46 connolly Exp $ --> </HEAD> NOTE - Some historical HTMLrefersimplementations incorrectly consider any `>' character to be thedocument type as well as the markup language for representing instancestermination ofthat document type. 2.6 Working with Structured Text An HTML document is likeatext file, except that some of the characters are markup. Markup (tags) define the structure of the document. To identify information as HTML, each HTML document Berners-Lee, Connolly, et. al. Page 14comment. 2.2.6. Example HTML2.0 February 8, 1995 should start with the prologue:Document <!DOCTYPE HTML PUBLIC "-//IETF//DTDHTML//EN//2.0"> NOTE: If the body ofHTML//EN"> <HTML> <!-- Here's atext/html body part does not begin withgood place to put adocument type declaration, an HTML user agent should infercomment. --> <HEAD> <TITLE>Structural Example</TITLE> </HEAD><BODY> <H1>First Header</H1> <P>This is a paragraph in theabove document type declaration.example HTMLdocuments should also contain an <HTML> tag atfile. Keep in mind that thebeginning oftitle does not appear in thefile, afterdocument text, but that theprologue, andheader (defined by H1) does.</P> <OL> <LI>First item in an</HTML> tag at the end. Within those tags,ordered list. <LI>Second item in anHTML document is organized as a head and a body, much like memo or a mail message. Within the head, youordered list. <UL COMPACT> <LI> Note that lists canspecify the title and other information about the document. Withinbe nested; <LI> Whitespace may be used to assist in reading thebody, you can structure text into paragraphs and lists as well as highlighting phrases and creating links. You do this usingHTMLelements. NOTE:source. </UL> <LI>Third item in an ordered list. </OL> <P>This is an additional paragraph. Technically,the start andend tags are not required forHTML, Head, and Body elementsparagraphs, although they areomissible; however, thisallowed. You can include character highlighting in a paragraph. <EM>This sentence of the paragraph isnot recommended sinceemphasized.</EM> Note that thehead/ body structure allows an implementation to determine certain properties of a document, such</P> end tag has been omitted. <P> <IMG SRC ="triangle.xbm" alt="Warning: "> Be sure to read these <b>bold instructions</b>. </BODY></HTML> 3. HTML asthe title, without parsing the entire document. 2.6.1an Internet Media Type An HTMLElements Inuser agent allows users to interact with resources which have HTMLdocuments, tags define the startrepresentations. At a minimum, it must allow users to examine andendnavigate the content ofheadings, paragraphs, lists, character highlighting and links. MostHTMLelements are identifieddocuments. HTML user agents should be able to preserve all formatting distinctions represented ina document as a start tag, which gives the element namean HTML document, andattributes, followedbe able to simultaneously present resources referred to by IMG elements. (they may ignore some formatting distinctions or IMG resources at thecontent, followed byrequest of theend tag. Start tags are delimited by < and >, and end tags are delimited by </user). Conforming HTML user agents should support form entry and>. Example: <H1>This is a Heading</H1> Some elements only have a start tag without an end tag. For example, to create a line break, you use the <BR> tag. Additionally,submission. 3.1. text/html media type This specification defines theend tags of some other elements, suchInternet Media Type[IMEDIA] (formerly referred to asParagraph (<P>), List Item (<LI>), Definition Term (<DT>), and Definition Description (<DD>) elements, may be omitted.the Content Type[MIME]) called `text/html'. Thecontent of an elementfollowing isa sequence of characters and nested elements. Some elements, such as anchors, cannot be nested. Anchors and character highlighting mayto beput inside other constructs. Berners-Lee, Connolly, et. al. Page 15 HTML 2.0 February 8, 1995 NOTE:registered with [IANA]. Media Type name text Media subtype name html Required parameters none Optional parameters version, charset Encoding considerations any encoding is allowed Security considerations see 3.3, "Security Considerations" TheSGML declaration for HTML specifies SHORTTAG YES, which means that thereoptional parameters areother valid syntaxes for tags, suchdefined asNET tags, <EM/.../; empty start tags, <>; and empty end tags, </>. Until support for these idioms is widely deployed, their use is strongly discouraged. 2.6.2 Names A name consists of a letter followed by upfollows: Version To help avoid future compatibility problems, the version parameter may be used to71 letters, digits, periods, or hyphens. Element names are not case sensitive, but entity names are. For example, <BLOCKQUOTE>, <BlockQuote>, and <blockquote> are equivalent, whereas & is different from &. In a start tag,give theelement name must immediately followversion number of thetag open delimiter <. 2.6.3 Attributes In a start tag, white space and attributes are allowed betweenspecification to which theelement name anddocument conforms. The version number appears at theclosing delimiter. An attribute typically consistsfront ofan attribute name, an equal sign,this document anda value (although some attributes may be just a value). White space is allowed aroundwithin theequal sign. The valuepublic identifier of theattributeHTML DTD. This specification defines version 2.0. There is no default. Charset The charset parameter (as defined in section 7.1.1 of RFC 1521[MIME]) may beeither: - A string literal, delimited by single quotes or double quotes and not containing any occurrences ofgiven to specify thedelimiting character. - A name token (acharacter encoding scheme used to represent the HTML document as a sequence ofletters, digits, periods, or hyphens) Inoctets. The default value is outside the scope of this specification; but for example,A istheelement name, HREFdefault is US-ASCII in theattribute name,context of MIME mail, andhttp://host/dir/file.html isISO-8859-1 in theattribute value: <A HREF="http://host/dir/file.html"> NOTE: Some non-SGML implementations consider any occurrence of the > character to signal the endcontext ofa tag. For compatibility with such implementations, when > appears in an attribute value, you may want to represent itHTTP. 3.2. HTML Document Representation A message entity with a content type of `text/html' represents anentity or numeric character reference (see Section 2.17.1), such as: <IMG SRC="eq1.jpg" alt="a > b"> Berners-Lee, Connolly, et. al. Page 16HTML2.0 February 8, 1995 To put quotes insidedocument, consisting ofquotes, you may use thea single text entity. The `charset' parameter (whether implicit or explicit) identifies a characterrepresentation " as in: <IMG SRC="image.jpg" alt="First "real" example">encoding scheme. Thelengthtext entity consists ofan attribute value is limited to 1024the charactersafter replacing entity and numericdetermined by this characterreferences. NOTE: Some non-SGMLencoding scheme and the octets of the body of the message entity. 3.2.1. Undeclared Markup Error Handling To facilitate experimentation and interoperability between implementationsallow any character except space or > in a name token. Attributes values must be quoted only if they don't satisfyof various versions of HTML, thesyntax forinstalled base of HTML user agents supports aname token. Attributes withsuperset of the HTML 2.0 language by reducing it to HTML 2.0: markup in the form of a start-tag or end-tag whose generic identifier is not declaredvalueis mapped to nothing during tokenization. Undeclared attributes are treated similarly. The entire attribute specification ofNAME, such as ISMAPan unknown attribute (i.e., the unknown attribute andCOMPACT, may be written using a minimized syntax. The markup: <UL COMPACT="compact"> canits value, if any) should bewritten using a minimized syntax: <UL COMPACT> NOTE: Some non-SGML implementations only understandignored. On theminimized syntax. 2.6.4 Special Characters Characters that are usedother hand, references torepresent markup (such as ampersand (&), lesser (<) and greater (>))undeclared entities shouldthemselvesberepresented by markup, using either entity or numeric character references.treated as data characters. Formore information, see Section 2.16. 2.6.5 Comments To include comments in an HTML document that willexample: <div class=chapter><h1>foo</h1><p>...</div> => <H1>,"foo",</H1>,<P>,"..." xxx <P ID=z23> yyy => "xxx ",<P>," yyy Let α and β beignored by the HTML user agent, surround them with <!--finite sets. => "Let α and-->. After the comment delimiter, all text up toβ be finite sets." Support for notifying thenext occurrenceuser of-->such errors isignored. Hence comments cannot be nested. White spaceencouraged. Information providers are warned that this convention isallowed between the closing -- and >, butnotbetween the opening <! and --. For example: <HEAD> <TITLE>HTML Guide: Recommended Usage</TITLE> <!-- Id: Text.html,v 1.6 1994/04/25 17:33:48 connolly Exp --> Berners-Lee, Connolly, et. al. Page 17 HTML 2.0 February 8, 1995 </HEAD> NOTE: Some historical HTML user agents incorrectly consider a > signbinding: unspecified behavior may result, as such markup is not conforming toterminatethis specification. 3.2.2. Conventional Representation of Newlines SGML specifies that acomment. 2.7 The Head Elementtext entity is a sequence of records, each beginning with a record start character andRelated Elements Only certain elements are allowedending with a record end character (code positions 10 and 13 respectively). (section 7.6.1, ``Record Boundaries'' inthe head of an HTML document. Elements[SGML]) [MIME] specifies thatmay be included in the heada body of type `text/*' is adocument are: 2.7.1 Head <HEAD> ... </HEAD> Level 0 The headsequence ofan HTML documentlines, each terminated by CRLF, that is octets 10, 13. In practice, HTML documents are frequently represented and transmitted using anunordered collectionend ofinformation about the document. It requires the Title element between <HEAD> and </HEAD> tags in this format: <HEAD> <TITLE>Introduction to HTML</TITLE> </HEAD> 2.7.2 Base Level 0 The Base element allowsline convention that depends on theURLconventions of thedocument itself to be recorded in situations in which the document may be read outsource ofcontext. URLs withinthedocument may be in a "partial" form relative to this base address. Wheredocument; frequently, that representation consists of CR only, LF only, or CR LF combination. Hence thebase address is not specified,decoding of the octets will often result in a text entity with some missing record start and record end characters. Since there is no ambiguity, HTML useragent uses the URL it used to access the documentagents are encouraged toresolve any relative URLs. The Base element has one attribute, HREF, which identifies the URL. 2.7.3 Isindex Level 0 The Isindex element tellsinfer the missing record start and end characters. An HTML user agentthat the document is an index document. As well as reading it, the reader may use a keyword search. The document can be queried with a keyword search by Berners-Lee, Connolly, et. al. Page 18 HTML 2.0 February 8, 1995 adding a question mark to theshould treat end ofthe document address, followed by a listline in any ofkeywords separated by plus signs. NOTE: The Isindex element is usually generated automatically byits variations as aserver. If added manually toword space in all contexts except preformatted text. Within preformatted text, an HTMLdocument, the HTMLuser agentassumes thatshould expect to treat any of theserver can handlethree common representations of end-of-line as starting asearch onnew line. 3.3. Security Considerations Anchors, embedded images, and all other elements which contain URIs as parameters may cause thedocument. To useURI to be dereferenced in response to user input. In this case, theIsindex element,security considerations of theserver must have a search engine that supports this element. 2.7.4 Link Level 1URI specification apply. TheLink element indicates a relationship between the documentwidely deployed methods for submitting forms requests -- HTTP andsome other object. A document may have any numberSMTP -- provide little assurance of confidentiality. Information providers who request sensitive information via forms -- especially by way ofLink elements. The Link element is empty (does not have a closing tag), but takes the same attributes astheAnchor element. Typical uses are to indicate authorship, related indexes`PASSWORD' type input field -- should be aware andglossaries, older or more recent versions, etc. Links can indicate a static tree structure in whichmake their users aware of the lack of confidentiality. > 4. Document Structure Elements To identify information as an HTML documentwas authored by pointing to a "parent" and "next" and "previous" document, for example. Servers may also allow linksconforming tobe added by those who do not havethis specification, each document should start with theright to alterprologue: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> NOTE - If the body of adocument. 2.7.5 Nextid Level 0 The Nextid element is a parameter read by and generated by text editing software to create unique identifiers. This tag takes a single attribute which is the next document-wide alpha-numeric identifier to be allocated of the form z123: <NEXTID N=Z27> When modifying a document, existing anchor identifiers shouldtext/html body part does notbe reused, as these identifiers may be referenced by other documents. Human writers ofbegin with a document type declaration, an HTMLusually use mnemonic alphabetical identifiers.user agent should infer the above document type declaration. HTML user agentsmay ignoreare required to support theNextid element. Support forabove document type declaration, theNextid element does not impactfollowing document type declarations, and no others. <!DOCTYPE HTMLuser agents Berners-Lee, Connolly, et. al. Page 19PUBLIC "-//IETF//DTD HTML 2.0February 8, 1995 in any way. 2.7.6 TitleStrict//EN"> <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict//EN"> In particular, they may support other formal public identifiers, or document types altogether. They may support an internal declaration subset with supplemental entity, element, and other markup declarations, or they may not. 4.1. HTML Document Element <HTML> ... </HTML> Level 0 The HTML document element is organized as a head and a body, much like a memo or a mail message. Within the head, you can specify the title and other information about the document. Within the body, you can structure text into paragraphs and lists, as well as highlight phrases and create links, using HTML elements. NOTE - The start and end tags for HTML, Head, and Body elements are omissible; however, this is not recommended since the head/body structure allows an implementation to determine certain properties of a document, such as the title, without parsing the entire document. < 4.2. Head <HEAD> ... </HEAD> Level 0 The head of an HTML document is an unordered collection of information about the document. The Title element is required. <HEAD> <TITLE>Introduction to HTML</TITLE> </HEAD> 4.3. Body <BODY> ... </BODY> Level 0 The Body element identifies the body component of an HTML document. Specifically, the body of a document may contain links, text, and formatting information within <BODY> and </BODY> tags. 4.4. Title <TITLE> ... </TITLE> Level 0 Every HTML document must contain a Title element. The title should identify the contents of the document in a global context, and may be used inahistory lists and as a label for the window displaying the document. Unlike headings, titles are nottypicallyrendered in the text of a document itself. The Title element must occur within the head of the document, andmaymust not contain anchors, paragraph tags, or highlighting. Only one title is allowed in a document.NOTE:NOTE - The length of a title is not limited; however, long titles may be truncated in some applications. To minimize this possibility, titles should be fewer than 64 characters. Also keep in mind that a short title, such as Introduction, may be meaningless out of context. An example of a meaningful title might be"Introduction``Introduction to HTMLElements." 2.7.7 MetaElements.'' 4.5. Base <BASE> Level10 TheMetaBase elementis used withinallows the URI of theHead element to embeddocumentmeta-information not defined by other HTML elements. Such information canitself to beextracted by servers/clients for userecorded inidentifying, indexing, and cataloging specializedsituations in which the documentmeta-information. Although it is generally preferable to use named elements that have well-defined semantics for each type of meta-information, such as a title, this element is provided for situations where strict SGML parsing is necessary and the local DTD is not extensible. In addition, HTTP servers canmay be readthe contentout of context. URIs within the documenthead to generate response headers corresponding to any elements definingmay be in avalue for``partial'' form relative to this base address[RELURL]. The Base element has one attribute, HREF, which identifies theattribute HTTP- EQUIV. This provides document authors a mechanism (not necessarilyabsolute base URI. 4.6. Isindex <ISINDEX> Level 0 The Isindex element tells thepreferred one) for identifying informationinterpreter thatshould be included intheresponse Berners-Lee, Connolly, et. al. Page 20 HTML 2.0 February 8, 1995 headers fordocument is anHTTP request. Attributes of the Meta element: HTTP-EQUIVindex. Thisattribute bindsmeans that theelementreader may request a keyword search on the resource by adding a question mark toan HTTP response header. Ifthesemanticsend of theHTTP response header nameddocument address, followed bythis attribute is known, then the contents can be processed based onawell-defined syntactic mapping whether or notlist of keywords separated by plus signs. The Isindex element is usually generated by theDTD includes anything about it. HTTP header names are not case sensitive. If not present,network server from which theNAME attribute should be used to identifydocument was obtained via a URI. The server must have a search engine that supports thismeta- information and it should not be used within an HTTP response header. NAME Meta-information name.feature for the resource. If theNAME attributedocument URI isnot present, the name can be assumed equalunknown to thevalue of HTTP-EQUIV. CONTENT The meta-information content tointerpreter, <isindex> must beassociated with the given name and/or HTTP response header. Examples Ifignored. 4.7. Link <LINK> Level 0 The Link element indicates a relationship between the documentcontains: <META HTTP-EQUIV="Expires" CONTENT="Tue, 04 Dec 1993 21:29:02 GMT"> <META HTTP-EQUIV="Keywords" CONTENT="Fred, Barney"> <META HTTP-EQUIV="Reply- to" content="fielding@ics.uci.edu (Roy Fielding)"> Expires: Tue, 04 Dec 1993 21:29:02 GMT Keywords: Fred, Barney Reply-to: fielding@ics.uci.edu (Roy Fielding) When the HTTP-EQUIV attributeand some other object. A document may have any number of Link elements. The Link element is empty (does notpresent,have a closing tag), but takes theserver should not generate an HTTP response header for this meta-information; e.g., <META NAME="IndexType" CONTENT="Service"> Do not usesame attributes as theMeta element to define information that should be associated with an existing HTMLAnchor element.Berners-Lee, Connolly, et. al. Page 21 HTML 2.0 February 8, 1995 Example of an inappropriate use of the Meta element: <META NAME="Title" CONTENT="The Etymology of Dunsel"> Do not name an HTTP-EQUIV equal to a response header that should typically only be generated by the HTTP server. Some inappropriate namesTypical uses are"Server", "Date",to indicate authorship, related indexes and"Last-modified". Whetherglossaries, older or more recent versions, etc. Links can indicate aname is inappropriate depends onstatic tree structure in which theparticular server implementation. It is recommended that servers ignore any Meta elements that specify HTTP-equivalents equal (case-insensitively)document was authored by pointing totheir own reserved response headers. 2.8 The Body Elementa ``parent'' andRelated Elements The following elements``next'' and ``previous'' document, for example. Servers may also allow links to beincluded inadded by those who do not have the right to alter the body ofan HTML document: 2.8.1 Body <BODY> ... </BODY>a document. 4.8. Meta <META> Level 0 TheBodyMETA elementidentifiesis used within thebody component of an HTML document. Specifically, the body of aHEAD element to embed documentmay contain links, text, and formatting information within <BODY>metainformation not defined by other HTML elements. META elements can be extracted by servers and/or clients for use in identifying, indexing, and</BODY> tags. 2.8.2 Address <ADDRESS> ... </ADDRESS> Level 0 The Addresscataloging specialized document metainformation. Although it is generally preferable to use named elements which have well-defined semantics for each type of metainformation (e.g. TITLE), the META elementspecifies such information as address, signatureis provided for situations where strict SGML parsing is necessary andauthorship, often atthetop or bottom of a document. Typically, an Addresslocal DTD isrendered in an italic typeface andnot extensible. HTML interpreters maybe indented. The Address element implies a paragraph break beforeuse the META element's content if they recognize andafter. Example of use: <ADDRESS> Newsletter editor<BR> J.R. Brown<BR> JimquickPost News, Jumquick, CT 01234<BR> Tel (123) 456 7890 Berners-Lee, Connolly, et. al. Page 22 HTML 2.0 February 8, 1995 </ADDRESS> 2.8.3 Anchor <A> ... </A> Level 0 An anchor is a marked text that isunderstand thestart and/or destination of a hypertext link. Anchor elements are definedsemantics identified by the<A> tag. The <A> tag accepts several attributes, but either theNAME orHREF attribute is required. Attributes ofHTTP-EQUIV attributes, and may treat the<A> tag: HREF Level 0 Ifcontent as metainformation (and not render it) even when they do not recognize theHREF attribute is present,name. In addition, HTTP servers may wish to read thetext betweencontent of theopening and closing anchor tags becomes hypertext. If this hypertext is selected by readers, they are moveddocument HEAD toanother document, orgenerate header fields corresponding to any elements defining adifferent location invalue for thecurrent document, whose network address is definedattribute HTTP-EQUIV. Note, however, that the method by which thevalueserver extracts document metainformation is not part ofthe HREF attribute. Example: See <A HREF="http://www.hal.com/">HaL</A>'s information for more details. Inthisexample, selecting "HaL" takes the reader to a document at http://www.hal.com. The formatspecification, nor can it be assumed by authors that any given server will be capable ofthe network addressextracting it. The META element only provides an extensible mechanism for identifying and embedding document metainformation - how it may be used isspecified inup to theURI specification for print readers. Withindividual server implementation and theHREF attribute,HTML interpreter. Attributes of theform HREF="#identifier" can referMETA element: HTTP-EQUIV This attribute binds the element toanother anchor inan HTTP header field. It means that if you know thesame document. Example: The <A HREF="document.html#glossary">glossary</A> defines terms used in this document. In this example, selecting "glossary" takessemantics of thereader to another anchor (i.e., <A NAME="glossary">Glossary</A>) inHTTP header field named by this attribute, then you can process thesame document (document.html). The NAME attribute is described below.contents based on a well-defined syntactic mapping, whether or not your DTD tells you anything about it. HTTP header field names are not case sensitive. If not present, theanchor is in another document, the HREFattributeBerners-Lee, Connolly, et. al. Page 23 HTML 2.0 February 8, 1995 mayNAME should berelativeused to identify this metainformation and thedocument's address or the specified base address (see 2.7.2 Base).content should not be used within an HTTP response header. NAMELevel 0Metainformation name. Ifpresent,the NAME attributeallowsis not present, theanchorname can be assumed to be equal to thetarget of a link. Thevalue of HTTP-EQUIV. CONTENT The metainformation content to be associated with theNAME attribute is an identifier for the anchor. Identifiersgiven name. If multiple META elements arearbitrary strings but must be unique withinprovided with theHTML document. Example of use: <A NAME="coffee">Coffee</A> is an example of ... ... An example of this is <A HREF="#coffee">coffee</A>. Another document can then makesame name, their combined contents-concatenated as areference explicitly to this anchor by putting the identifier aftercomma-separated list-is theaddress, separated by a hash sign: <A NAME="drinks.html#coffee"> TITLE Level 1 The TITLE attribute is informational only.value associated with that name. Examples Ifpresent, the TITLE attribute should provide the title ofthe documentwhose address is given bycontains: <META HTTP-EQUIV="Expires" CONTENT="Tue, 04 Dec 1993 21:29:02 GMT"> <meta http-equiv="Keywords" CONTENT="Fred, Barney"> <META HTTP-EQUIV="Reply-to" content="fielding@ics.uci.edu (Roy Fielding)"> then theHREF attribute. The TITLE attribute is useful for at least two reasons. The HTML user agentserver (if so configured) maydisplayinclude thetitlefollowing headers: Expires: Tue, 04 Dec 1993 21:29:02 GMT Keywords: Fred, Barney Reply-to: fielding@ics.uci.edu (Roy Fielding) as part of thedocument priorHTTP response toretrieving it, for example, asamargin noteGET oron a small box whileHEAD request for that document. When themouseHTTP-EQUIV attribute isover the anchor, or whilenot present, thedocument is being loaded. Another reason is that documents that areserver should notmarked up text, such as graphics, plain textgenerate an HTTP response header for the metainformation; e.g., <META NAME="IndexType" CONTENT="Service"> would never generate an HTTP response header, but would still allow HTML interpreters to identify andGopher menus, do not have titles.make use of that metainformation. TheTITLE attribute canMeta element should never be used toprovide a title to such documents. When using the TITLE attribute, the titledefine information that should bevalid and unique for the destination document. REL Level 1 The REL attribute gives the relationship(s) described by the hypertext link fromassociated with an existing HTML element. An example of an inappropriate use of theanchorMeta element is: <META NAME="Title" CONTENT="The Etymology of Dunsel"> Do not name an HTTP-EQUIV equal tothe target. The Berners-Lee, Connolly, et. al. Page 24 HTML 2.0 February 8, 1995 value isacomma-separated list of relationship values. Values and their semantics willresponse header that should normally only beregisteredgenerated by theHTML registration authority. The default relationship if none other is given is void. The REL attribute is only used whenHTTP server. Example names that are inappropriate include ``Server'', ``Date'', and ``Last-modified'' - theHREF attributeexact list of inappropriate names ispresent. REVdependent on the particular server implementation. We recommend that servers ignore any META elements which specify HTTP-equivalents which are equal (case-insensitively) to their own reserved response headers. 4.9. Nextid <NEXTID> Level10 TheREVNextid element is a parameter read and generated by text editing software to create unique identifiers. This tag takes a single attribute which is thesame as the REL attribute, but the semantics of the link type are in the reverse direction. A link from Anext document-wide alpha- numeric identifier toB with REL="X" expressesbe allocated of thesame relationship asform z123: <NEXTID N=Z27> When modifying alink from B to A with REV="X". Andocument, existing anchor identifiers should not be reused, as these identifiers mayhave both REL and REV attributes. URN Level 1 If present, the URN attribute specifies a uniform resource name (URN) for a target document. The format of URNs is under discussion (1994)be referenced byvarious working groups of the Internet Engineering Task Force. METHODS The METHODS attributesother documents. Human writers ofanchors and links provide information about the functions that the userHTML usually use mnemonic alphabetical identifiers. HTML interpreters mayperform on an object. These are more accurately given byignore theHTTP protocol when it is used, but it may, for similar reasons asNextid element. Support for theTITLE attribute, be useful to include the information in advanceNextid element does not impact HTML interpreters inthe link. For example, theany way. 5. Character Content An HTML user agentmay chose a different renderingshould present the body of an HTML document as afunctioncollection ofthe methods allowed;typeset paragraphs and preformatted text. Except forexample, something thatthe <PRE> element, each block structuring element issearchable may getregarded as adifferent icon. The valueparagraph by taking the data characters in its content and the content of its descendant elements, concatenating them, and splitting theMETHODS attribute is a commaresult into words, separatedlist of HTTP methods supportedbythe object for public use. See also: 2.7.4 Link 2.8.4 Blockquote <BLOCKQUOTE> ... </BLOCKQUOTE> Level 0 Berners-Lee, Connolly, et. al. Page 25 HTML 2.0 February 8, 1995space, tab, or record end characters (and perhaps hyphen characters). TheBlockquote elementsequence of words isused to contain text quoted from another source. A typical rendering might be a slight extra left and right indent, and/or italic font. The Blockquote element causestypeset as a paragraphbreak, and typically provides space above and below the quote. Single-font rendition may reflect the quotation style of Internet mailbyputtingbreaking it into lines. 5.1. The ISO Latin 1 Character Repertoire The minimum character repertoire supported by all conforming HTML user agents is Latin Alphabet Nr. 1, or simply Latin-1. Latin-1 includes characters from most Western European languages, as well as avertical linenumber ofgraphiccontrol characters. Latin-1 also includes a non-breaking space, a soft hyphen indicator, 93 graphical characters,such as8 unassigned characters, and 25 control characters. NOTE - Use thegreater than symbol (>), innon-breaking space and soft hyphen indicator characters is discouraged because support for them is not widely deployed. In SGML applications, theleft margin. Exampleuse ofuse: I think the poem ends <BLOCKQUOTE> <P>Soft you now,control characters is limited in order to maximize thefair Ophelia. Nymph,chance of successful interchange over heterogeneous networks and operating systems. In HTML, only three control characters are allowed: Horizontal Tab (HT, encoded as 9 decimal inthy orisons, be all my sins remembered. </BLOCKQUOTE> but I am not sure. 2.8.5 Headings <H1> ... </H1> through <H6> ... </H6> Level 0US-ASCII and ISO-8859-1), Carriage Return, and Line Feed. The HTMLdefines six levelsDTD references the Added Latin 1 entity set, to allow mnemonic representation ofheading. A Heading element implies allLatin 1 characters using only thefont changes, paragraph breaks beforewidely supported ASCII character repertoire. For example: Kurt Gödel was a famous logician andafter,mathematician. See 11.4.2, "ISO Latin 1 Character Entity Set" for a table of the ``Added Latin 1'' entities, andwhite space necessary to render14.1, "The ISO-8859-1 Coded Character Set" for a table of theheading. The highest levelcode positions ofheadings is H1, followed by H2 ... H6. ExampleISO-8859-1. 6. Data Elements 6.1. Line Break <BR> Level 0 The Line Break element specifies that a new line must be started at the given point. A new line indents the same as that of line-wrapped text. Example of use:<H1>This<P> Pease porridge hot<BR> Pease porridge cold<BR> Pease porridge in the pot<BR> Nine days old. 6.2. Horizontal Rule <HR> Level 0 A Horizontal Rule element is aheading</H1> Here is somedivider between sections of text<H2>Second level heading</H2> Here is some more text. The renderingsuch as a full width horizontal rule or equivalent graphic. Example ofheadingsuse: <HR> <ADDRESS>February 8, 1995, CERN</ADDRESS> </BODY> 6.3. Image <IMG> Level 0 The Image element isdetermined byused to incorporate in-line graphics (typically icons or small graphics) into an HTML document. This element cannot be used for embedding other HTML text. HTML interpreters that cannot render in-line images ignore the Image element unless it contains the ALT attribute. Note that some HTMLuser agent,interpreters can render linked graphics buttypical renderings are: <H1> ... </H1> Bold, very-large font, centered. Onenot in-line graphics. If a graphic is essential, you may want to create a link to it rather than to put it in-line. If the graphic is not essential, then the Image element is appropriate. The Image element, which is empty (no closing tag), has these attributes: ALIGN The ALIGN attribute accepts the values TOP ortwo blank lines above and below. Berners-Lee, Connolly, et. al. Page 26 HTML 2.0 February 8, 1995 <H2> ... </H2> Bold, large font, flush-left. OneMIDDLE ortwo blank lines above and below. <H3> ... </H3> Italic, large font, slightly indented fromBOTTOM, which specifies if theleft margin. One or two blank lines above and below. <H4> ... </H4> Bold, normal font, indented more than H3. One blankfollowing lineabove and below. <H5> ... </H5> Italic, normal font, indentedof text is aligned with the top, middle, or bottom of the graphic. ALT Optional text asH4. One blank line above. <H6> ... </H6> Bold, indented samean alternative to the graphic for rendering in non-graphical environments. Alternate text should be provided whenever the graphic is not rendered. Alternate text is mandatory for Level 0 documents. Example of use: <IMG SRC="triangle.xbm" ALT="Warning:"> Be sure to read these instructions. ISMAP The ISMAP (is map) attribute identifies an image asnormal text, more than H5. One blank line above. Although heading levelsan image map. Image maps are graphics in which certain regions are mapped to URIs. By clicking on different regions, different resources can beskipped (for example,accessed fromH1the same graphic. Example of use: <A HREF="http://machine/htbin/imagemap/sample"> <IMG SRC="sample.xbm" ISMAP> </A> SRC The value of the SRC attribute is the URI of the document toH3), this practicebe embedded; only images can be embedded, not HTML text. Its syntax isdiscouragedthe same asskipping heading levels may produce unpredictable results when generating other representations from HTML. 2.9 Overviewthat of the HREF attribute of the `<A>' tag. SRC is mandatory. Image elements are allowed within anchors. Example ofCharacter-Leveluse: <IMG SRC="triangle.xbm">Be sure to read these instructions. 7. Character Format ElementsLevel 2 (all elements) Character-levelCharacter format elements are used to specify either the logical meaning or the physical appearance of marked text without causing a paragraph break. Like most other elements,character-levelcharacter format elements include both opening and closing tags. Only the characters between the tags are affected: This is <EM>emphasized</EM> text.Character-levelCharacter format tags may be ignored by minimal HTML applications.Character-levelCharacter format tags are interpreted from left to right as they appear in the flow of text. Level 1HTML user agentsinterpreters must render highlighted text distinctly fromBerners-Lee, Connolly, et. al. Page 27 HTML 2.0 February 8, 1995plain text. Additionally, EM content must be rendered as distinct from STRONG content, and B content must rendered as distinct from I content.Character-levelCharacter format elements may be nested within the content of othercharacter-level elements;character format elements; however, HTMLuser agentsinterpreters are not required to render nestedcharacter- levelcharacter format elements distinctly from non-nested elements: plain <B>bold <I>italic</I></B> may the rendered the same as plain <B>bold </B><I>italic</I> 7.1. Semantic Format Elements Note that typical renderings forinformation typesemantic format elements vary between applications. If a specific rendering isnecessary,necessary - for example, when referring to a specific text attribute as in"The``The italic parts aremandatory",mandatory'' - a physical formating element can be used to ensure that the intended rendered is used where possible.2.10 Information Type ElementsNote that differentinformation typesematic elements may be rendered in the same way.2.10.17.1.1. Citation <CITE>...</CITE> Level 1 The Citation element specifies acitation;citation, typically rendered as italics.2.10.27.1.2. Code <CODE> ... </CODE> Level 1 The Code element indicates an example ofcode;code, typically renderedasin a monospaced. Dofont. This should notconfusebe confused with the Preformatted Text element.2.10.37.1.3. Emphasis <EM> ... </EM> Level 1 The Emphasis element indicates typographic emphasis, typically rendered as italics.2.10.47.1.4. Keyboard <KBD> ... </KBD>Berners-Lee, Connolly, et. al. Page 28 HTML 2.0 February 8, 1995Level 1 The Keyboard element indicates text typed by auser;user, typically renderedasin a monospaced. It mightfont. This is commonlybeused inaninstructionmanual. 2.10.5manuals. 7.1.5. Sample <SAMP> ... </SAMP> Level 1 The Sample element indicates a sequence of literalcharacters;characters, typically renderedas monospaced. 2.10.6in a monospaced font. 7.1.6. Strong <STRONG> ... </STRONG> Level 1 The Strong element indicates strong typographic emphasis, typically rendered in bold.2.10.77.1.7. Variable <VAR> ... </VAR> Level 1 The Variable element indicates a variablename;name, typically rendered as italic.2.11 Character7.2. Physical Format ElementsCharacterPhysical format elements are used to specify the format of marked text.Example of use: 2.11.17.2.1. Bold <B> ... </B> Level 1 The Bold element specifies that the text should be rendered in boldface, where available. Otherwise, an alternative mapping is allowed.2.11.27.2.2. Italic <I> ... </I> Level 1 The Italic element specifies that the text should be rendered in an italic font, where available. Otherwise, an alternative mapping is allowed.2.11.37.2.3. Teletype <TT> ... </TT>Berners-Lee, Connolly, et. al. Page 29 HTML 2.0 February 8, 1995Level 1 The Teletype element specifies that the text should be rendered in a fixed-width typewriter font.2.12 Image Element <IMG>8. Hyperlink Elements 8.1. Anchor <A> ... </A> Level 0The Image elementAn anchor isused to incorporate in-line graphics (typically icons or small graphics) into an HTML document. This element cannot be used for embedding other HTML text. HTML user agents that cannot render in-line images ignore the Image element unless it contains the ALT attribute. Note that some HTML user agents can render linked graphics but not in-line graphics. Ifagraphicmarked section of text that isessential, you may want to create a link to it rather than to put it in-line. Ifthegraphic is not essential, thenstart and/or destination of a hypertext link. Anchor elements are defined by theImage element is appropriate. The Image element, which is empty (no closing tag), has these attributes: ALIGN`<A>' tag. TheALIGN attribute`<A>' tag acceptsthe values TOP or MIDDLE or BOTTOM, which specifies if the following lineseveral attributes; at least one oftext is aligned withthetop, middle, or bottomNAME and HREF attributes is required. Attributes of thegraphic. ALT Optional text as an alternative to the graphic for rendering in non-graphical environments. Alternate text should be provided whenever`<A>' tag: 8.1.1. HREF If thegraphicHREF attribute isnot rendered. Alternatepresent, the text between the opening and closing anchor tags becomes hypertext. If this hypertext ismandatory for Level 0 documents. Example of use: <IMG SRC="triangle.gif" ALT="Warning:"> Be sure to read these instructions. ISMAP The ISMAP (is map) attribute identifies an image as an image map. Image maps are graphics in which certain regionsselected by readers, they aremappedmoved toURLs. By clicking on different regions,another document, or to a differentresources can be accessed fromlocation in thesame graphic. Examplecurrent document, whose network address is defined by the value ofuse: Berners-Lee, Connolly, et. al. Page 30 HTML 2.0 February 8, 1995the HREF attribute. Example: See <AHREF="http://machine/htbin/imagemap/sample"> <IMG SRC="sample.gif" ISMAP> </A> SRCHREF="http://www.hal.com/">HaL</A>'s information for more details. In this example, selecting ``HaL'' takes the reader to a document at http://www.hal.com. Thevalueformat of theSRC attributenetwork address is specified in theURL ofURI specification for print readers. With thedocument to be embedded; only imagesHREF attribute, the form HREF=``#identifier'' canbe embedded, not HTML text. Its syntax isrefer to another anchor in the sameas that ofdocument. Example: The <A HREF="#glossary">glossary</A> defines terms used in this document. In this example, selecting ``glossary'' takes theHREFreader to another anchor (i.e., <A NAME=``glossary''>Glossary</A>) in the same document. The NAME attributeofis described below. If the<A> tag. SRCanchor ismandatory. Image elements are allowed within anchors. Example of use: <IMG SRC ="triangle.gif">Be surein another document, the HREF attribute may be relative to the document's address or the specified base address (see 4.5, "Base"). 8.1.2. NAME If present, the NAME attribute allows the anchor toread these instructions. 2.13 List Elements HTML supports several types of lists, all of which maybenested. 2.13.1 Definition List <DL> ... </DL> Level 0 A definition list isthe target of alistlink. The value ofterms and corresponding definitions. Definition lists are typically formatted withtheterm flush-left andNAME attribute is an identifier for thedefinition, formatted paragraph style, indented afteranchor. Identifiers are arbitrary strings but must be unique within theterm.HTML document. Example of use:<DL> <DT>Term<DD>This<A NAME="coffee">Coffee</A> isthe definitionan example ofthe first term. <DT>Term<DD>This... ... An example of this is <A HREF="#coffee">coffee</A>. Another document can then make a reference explicitly to this anchor by putting thedefinition ofidentifier after thesecond term. </DL>address, separated by a hash sign: <A HREF="drinks.html#coffee"> 8.1.3. TITLE The TITLE attribute is informational only. If present, theDT term does not fit inTITLE attribute should provide theDT column (one thirdtitle of thedisplay area), it may be extended across the page with the DD section moved todocument whose address is given by thenext line, or itHREF attribute. The TITLE attribute is useful for at least two reasons. The HTML interpreter maybe wrapped onto successive lines ofdisplay theleft hand column. Single occurrencestitle of the document prior to retrieving it, for example, as a<DT> tag withoutmargin note or on asubsequent <DD> tag are allowed, and havesmall box while thesame significance as ifmouse is over the<DD> tag had been present with no text. Berners-Lee, Connolly, et. al. Page 31 HTML 2.0 February 8, 1995 The opening list tag must be <DL> and must be immediately followed byanchor, or while thefirst term (<DT>).document is being loaded. Another reason is that documents that are not marked up text, such as graphics, plain text and Gopher menus, do not have titles. Thedefinition list typeTITLE attribute cantake the COMPACT attribute, which suggests that a compact renderingbeused, because the list items are small and/or the entire list is large. Unless youused to provide a title to such documents. When using theCOMPACTTITLE attribute, theHTML user agent may leave white space between successive DT, DD pairs.The COMPACTtitle should be valid and unique for the destination document. 8.1.4. REL The REL attributemay also reducegives thewidth ofrelationship(s) described by theleft-hand (DT) column. If usinghypertext link from theCOMPACT attribute,anchor to theopeningtarget. The value is a whitespace-separated listtag must be <DL COMPACT>, which mustof relationship names. Relationship names and their semantics will beimmediately followedregistered by thefirst <DT> tag: <DL COMPACT> <DT>Term<DD>ThisW3 Consortium. The default relationship is void. The REL attribute is only used when thefirst definition in compact format. <DT>Term<DD>ThisHREF attribute is present. 8.1.5. REV The REV attribute is thesecond definitionsame as the REL attribute, but the semantics of the link type are incompact format. </DL> 2.13.2 Directory List <DIR> ... </DIR> Level 0the reverse direction. A link from ADirectory List element is usedtopresentB with REL=``X'' expresses the same relationship as alist of items containing uplink from B to20 characters each. Items in a directory listA with REV=``X''. An anchor maybe arranged in columns, typically 24 characters wide.have both REL and REV attributes. 8.1.6. URN If present, theHTML user agent can optimize the column width as functionURN attribute specifies a uniform resource name (URN) for a target document. The format of URNs is under discussion (1995) by various working groups of thewidthsInternet Engineering Task Force. 8.1.7. METHODS The METHODS attributes ofindividual elements, so muchanchors and links provide information about thebetter. A directory list must begin withfunctions that the<DIR> tag which is immediately followeduser may perform on an object. These are more accurately given bya <LI> (list item) tag: <DIR> <LI>A-H<LI>I-M <LI>M-R<LI>S-Z </DIR> 2.13.3 Menu List <MENU> ... </MENU> Level 0 A menu listthe HTTP protocol when it is used, but it may, for similar reasons as for the TITLE attribute, be useful to include the information in advance in the link. For example, the HTML interpreter may chose alistdifferent rendering as a function ofitems with typically one line Berners-Lee, Connolly, et. al. Page 32 HTML 2.0 February 8, 1995 per item. The menu list style is more compact thanthestyle of an unordered list. A menu list must begin with a <MENU> tag whichmethods allowed; for example, something that isimmediately followed bysearchable may get a<LI> (list item) tag: <MENU> <LI>First item indifferent icon. The value of thelist. <LI>Second item inMETHODS attribute is a whitespace-separated list of HTTP methods supported by thelist. <LI>Third itemobject for public use. 9. Block Structuring Elements The following elements may be included in thelist. </MENU> 2.13.4 Ordered List <OL>body of an HTML document: 9.1. Paragraph <P> ...</OL> Level 0 The Ordered List element is used to present a numbered list of items, sorted by sequence or order of importance. An ordered list must begin with the <OL> tag which is immediately followed by a <LI> (list item) tag: <OL> <LI>Click the Web button to open the Open the URL window. <LI>Enter the URL number in the text field of the Open URL window. The Web document you specified is displayed. <LI>Click highlighted text to move from one link to another. </OL> The Ordered List element can take the COMPACT attribute, which suggests that a compact rendering be used. 2.13.5 Unordered List <UL> ... </UL> Level 0 The Unordered List element is used to present a list of items which is typically separated by white space and/or marked by bullets. An unordered list must begin with the <UL> tag which is immediately followed by a <LI> (list item) tag: <UL> <LI>First list item Berners-Lee, Connolly, et. al. Page 33 HTML 2.0 February 8, 1995 <LI>Second list item <LI>Third list item </UL> 2.14 Other Elements 2.14.1 Paragraph <P></P> Level 0 The Paragraph element indicates a paragraph. The exact indentation,leading,leading space, etc. of a paragraph is not defined and may be a function of other tags, style sheets, etc. Typically, paragraphs are surrounded by a vertical space of one line or half a line. This is typically not the case within the Address element andoris never the case within the Preformatted Text element. With some HTMLuser agents,interpreters, the first line in a paragraph is indented. Example of use: <H1>This Heading Precedes the Paragraph</H1> <P>This is the text of the first paragraph. <P>This is the text of the second paragraph. Although you do not need to start paragraphs on new lines, maintaining this convention facilitates documentmaintenance.maintenance.</P> <P>This is the text of a thirdparagraph. 2.14.2paragraph.</P> 9.2. Preformatted Text <PRE> ... </PRE> Level 0 The Preformatted Text element presents blocks of text in fixed-width font, and so is suitable for text that has been formatted on screen. The <PRE> tag may be used with the optional WIDTHattribute, which is a Level 1 feature.attribute. The WIDTH attribute specifies the maximum number of characters for a line and allows the HTMLuser agentinterpreter to select a suitable font and indentation. If the WIDTH attribute is not present, a width of 80 characters is assumed. Where the WIDTH attribute is supported, widths of 40, 80 and 132 characters should be presented optimally, with other widths being rounded up.Berners-Lee, Connolly, et. al. Page 34 HTML 2.0 February 8, 1995Within preformatted text:-* Line breaks within the text are rendered as a move to the beginning of the next line.- The <P> tag should not be used. If found, it should be rendered as a move to the beginning of the next line. -* Anchor elements and character highlighting elements may be used.-* Elements that define paragraph formatting (headings, address, etc.) must not be used.-* The horizontal tab character (encoded in US-ASCII and ISO-8859-1 as decimal 9) must be interpreted as the smallest positive nonzero number of spaces which will leave the number of characters so far on the line as a multiple of 8. Its use is not recommended however.NOTE:NOTE - Som historical documents contain <P> tags in <PRE> elements. User agents are engcouraged to treat this a a line break. A <P> tag followed by a newline character should produce only one line break, not a line break plus a blank line. NOTE - References to the"beginning``beginning of a newline"line'' do not imply that the renderer is forbidden from using a constant left indent for rendering preformatted text. The left indent may be constrained by the width required. Example of use: <PRE WIDTH="80"> This is an example line. </PRE>NOTE:NOTE - Within a Preformatted Text element, the constraint that the rendering must be on a fixed horizontal character pitch may limit or prevent the ability of the HTMLuser agentinterpreter to faithfully renderhighlighting elements specially. 2.14.3 Line Break <BR>character formatting elements. 9.3. Address <ADDRESS> ... </ADDRESS> Level 0 TheLine BreakAddress element specifiesthat a new line must be startedsuch information as address, signature and authorship, often at thegiven point. A new line indents the same Berners-Lee, Connolly, et. al. Page 35 HTML 2.0 February 8, 1995 as thattop or bottom ofline-wrapped text.a document. Typically, an Address is rendered in an italic typeface and may be indented. The Address element implies a paragraph break before and after. Example of use:<P> Pease porridge hot<BR> Pease porridge cold<BR> Pease porridge in the pot<BR> Nine days old. 2.14.4 Horizontal Rule <HR><ADDRESS> Newsletter editor<BR> J.R. Brown<BR> JimquickPost News, Jumquick, CT 01234<BR> Tel (123) 456 7890 </ADDRESS> 9.4. Blockquote <BLOCKQUOTE> ... </BLOCKQUOTE> Level 0A Horizontal RuleThe Blockquote element is used to contain text quoted from another source. A typical rendering might be adivider between sectionsslight extra left and right indent, and/or italic font. The Blockquote element causes a paragraph break, and typically provides space above and below the quote. Single-font rendition may reflect the quotation style oftextInternet mail by putting a vertical line of graphic characters, such asa full width horizontal rule or equivalent graphic.the greater than symbol (>), in the left margin. Example of use:<HR> <ADDRESS>February 8, 1995, CERN</ADDRESS> </BODY> 2.15 Form Elements Forms are created by placing input fields within paragraphs, preformatted/literal text, and lists. This gives considerable flexibility in designingI think thelayout of forms. The following elements (all are HTML 2 features) are used to create forms: FORM A form within a document. INPUT One input field. OPTION One option within a Select element. SELECT Berners-Lee, Connolly, et. al. Page 36 HTML 2.0 February 8, 1995 A selection from a finite setpoem ends <BLOCKQUOTE> <P>Soft you now, the fair Ophelia. Nymph, in thy orisons, be all my sins remembered. </BLOCKQUOTE> but I am not sure. 9.5. Headings <H1> ... </H1> through <H6> ... </H6> Level 0 HTML defines six levels ofoptions. TEXTAREAheading. Amulti-line input field. Each variable field is defined by an Input, Textarea, or OptionHeading element implies all the font changes, paragraph breaks before andmust have an NAME attributeafter, and white space necessary toidentify its value in the data returned whenrender theformheading. The highest level of headings issubmitted.H1, followed by H2 ... H6. Example ofuse (a questionnaire form): <H1>Sample Questionnaire</H1> <P>Please fill out this questionnaire: <FORM METHOD="POST" ACTION="http://www.hal.com/sample"> <P>Your name: <INPUT NAME="name" size="48"> <P>Male <INPUT NAME="gender" TYPE=RADIO VALUE="male"> <P>Female <INPUT NAME="gender" TYPE=RADIO VALUE="female"> <P>Number in family: <INPUT NAME="family" TYPE=text> <P>Cities in which you maintainuse: <H1>This is aresidence: <UL> <LI>Kent <INPUT NAME="city" TYPE=checkbox VALUE="kent"> <LI>Miami <INPUT NAME="city" TYPE=checkbox VALUE="miami"> <LI>Other <TEXTAREA NAME="other" cols=48 rows=4></textarea> </UL> Nickname: <INPUT NAME="nickname" SIZE="42"> <P>Thank you for responding to this questionnaire. <P><INPUT TYPE=SUBMIT> <INPUT TYPE=RESET> </FORM> In the example above, the <P> and <UL> tags have been used to lay out theheading</H1> Here is some textand input fields.<H2>Second level heading</H2> Here is some more text. TheHTML user agentrendering of headings isresponsible for handling which field will currently get keyboard input. Many platforms have existing conventions for forms, for example, using Tab and Shift keys to move the keyboard focus forwards and backwards between fields, and usingdetermined by theEnter key to submit the form. In the example, the SUBMITHTML interpreter, but typical renderings are: <H1> ... </H1> Bold, very-large font, centered. One or two blank lines above andRESET buttons are specified explicitly with special purpose fields. The SUBMIT button is used to e- mail the formbelow. <H2> ... </H2> Bold, large font, flush-left. One orsend its contents to the server as specified by the ACTION attribute, while RESET resets the fields to their initial values. When the form consists of a single text field, it may be appropriate to leave such buttons outtwo blank lines above andrely on the Enter key. The Input element is used for abelow. <H3> ... </H3> Italic, largevariety of types of input fields. Berners-Lee, Connolly, et. al. Page 37 HTML 2.0 February 8, 1995 To let users enterfont, slightly indented from the left margin. One or two blank lines above and below. <H4> ... </H4> Bold, normal font, indented more thanoneH3. One blank lineof text, use the Textarea element. 2.15.1 Representing Choices The radio buttonabove andcheckbox types of input fieldbelow. <H5> ... </H5> Italic, normal font, indented as H4. One blank line above. <H6> ... </H6> Bold, indented same as normal text, more than H5. One blank line above. Although heading levels can beusedskipped (for example, from H1 tospecify multiple choice forms in which every alternativeH3), this practice isvisiblediscouraged aspartskipping heading levels may produce unpredictable results when generating other representations from HTML. 9.6. List Elements HTML supports several types of lists, all ofthe form. An alternative is to use the Select elementwhichis typically rendered in a more compact fashion as a pull down combo list. 2.15.2 Form <FORM>may be nested. 9.6.1. Definition List <DL> ...</FORM></DL> Level2 The Form element0 A definition list isused to delimit a data input form. There can be several forms inasingle document, butlist of terms and corresponding definitions. Definition lists are typically formatted with theForm element can't be nested. The ACTION attribute is a URL specifyingterm flush-left and thelocation to whichdefinition, formatted paragraph style, indented after thecontentsterm. Example ofthe form is submitted to elicit a response. If the ACTION attributeuse: <DL> <DT>Term<DD>This ismissing,theURLdefinition of thedocument itself is assumed. The way datafirst term. <DT>Term<DD>This issubmitted varies withtheaccess protocoldefinition of theURL, and withsecond term. </DL> If thevalues ofDT term does not fit in theMETHOD and ENCTYPE attributes. In general: -DT column (one third of theMETHOD attribute selects variations indisplay area), it may be extended across theprotocol. -page with theENCTYPE attribute specifiesDD section moved to theformatnext line, or it may be wrapped onto successive lines of thesubmitted data in case the protocol does not imposeleft hand column. Single occurrences of aformat itself. The Level 2 specification defines<DT> tag without a subsequent <DD> tag are allowed, andrequires support for the HTTP access protocol only. Whenhave theACTION attribute is set to an HTTP URL,same significance as if theMETHOD attribute<DD> tag had been present with no text. The opening list tag must beset to an HTTP method as defined by the HTTP method specification in<DL> and must be immediately followed by theIETF draft HTTP standard.first term (<DT>). Thedefault METHOD is GET, although for many applications,definition list type can take thePOST method mayCOMPACT attribute, which suggests that a compact rendering bepreferred. Withused, because thepost method,list items are small and/or theENCTYPE attributeentire list isa MIME type specifyinglarge. Unless you provide theformat ofCOMPACT attribute, theposted data; by Berners-Lee, Connolly, et. al. Page 38HTML2.0 February 8, 1995 default, is application/x-www-form-urlencoded. Under any protocol, the submitted contents of the form logically consist of name/valueinterpreter may leave white space between successive DT, DD pairs. Thenames are usually equal toCOMPACT attribute may also reduce theNAME attributeswidth of thevarious interactive elements inleft-hand (DT) column. If using theform. NOTE: The names are not guaranteed to be unique keys, nor areCOMPACT attribute, thenames of form elements required toopening list tag must bedistinct. The values encode<DL COMPACT>, which must be immediately followed by theuser's input tofirst <DT> tag: <DL COMPACT> <DT>Term<DD>This is thecorresponding interactive elements. Elements capable of displaying a textual or numerical value will return a name/value pair even when they receive no explicit user input. 2.15.3 Input <INPUT>first definition in compact format. <DT>Term<DD>This is the second definition in compact format. </DL> 9.6.2. Directory List <DIR> ... </DIR> Level2 The Input0 A Directory List elementrepresentsis used to present afield whose contentslist of items containing up to 20 characters each. Items in a directory list may beedited byarranged in columns, typically 24 characters wide. If theuser. AttributesHTML interpreter can optimize the column width as function of theInput element: ALIGN Vertical alignmentwidths of individual elements, so much theimage. For use onlybetter. A directory list must begin withTYPE=IMAGE in HTML level 2. The possible values are exactly the same as for the ALIGN attribute oftheimage element. CHECKED Indicates that<DIR> tag which is immediately followed by acheckbox or radio button<LI> (list item) tag: <DIR> <LI>A-H<LI>I-M <LI>M-R<LI>S-Z </DIR> 9.6.3. Menu List <MENU> ... </MENU> Level 0 A menu list isselected. Unselected checkboxes and radio buttons do not return name/value pairs when the forma list of items with typically one line per item. The menu list style issubmitted. MAXLENGTH Indicatesmore compact than themaximum numberstyle ofcharacters that can be entered intoan unordered list. A menu list must begin with atext field. This can be greater than specified<MENU> tag which is immediately followed by a <LI> (list item) tag: <MENU> <LI>First item in theSIZE attribute,list. <LI>Second item inwhich casethefield will scroll appropriately. The default number of characters is unlimited. NAME Symbolic name used when transferringlist. <LI>Third item in theform's Berners-Lee, Connolly, et. al. Page 39 HTML 2.0 February 8, 1995 contents.list. </MENU> 9.6.4. Ordered List <OL> ... </OL> Level 0 TheNAME attribute is required for most input types andOrdered List element isnormallyused toprovide a unique identifier for a field, or forpresent alogically related groupnumbered list offields. SIZE Specifies the sizeitems, sorted by sequence orprecisionorder ofthe field according to its type. For example, to specify a fieldimportance. An ordered list must begin with the <OL> tag which is immediately followed by avisible width of 24 characters: INPUT TYPE=text SIZE="24" SRC A URL or URN specifying an image. For use only with TYPE=IMAGE in HTML Level 2. TYPE Defines the type of data<LI> (list item) tag: <OL> <LI>Click thefield accepts. DefaultsWeb button tofree text. Several types of fields can be defined withopen thetype attribute: CHECKBOX Used for simple Boolean attributes, or for attributes that can take multiple values atOpen thesame time. The latter is represented by a number of checkbox fields each of which hasURI window. <LI>Enter thesame name. Each selected checkbox generates a separate name/value pairURI number in thesubmitted data, even if this results in duplicate names. The default value for checkboxes is "on". HIDDEN Notext fieldis presented to the user, but the contentof thefieldOpen URI window. The Web document you specified issent with the submitted form. This value may be useddisplayed. <LI>Click highlighted text totransmit state information about client/server interaction. IMAGE An image field upon which youmove from one link to another. </OL> The Ordered List element canclick with a pointing device, causingtake theform toCOMPACT attribute, which suggests that a compact rendering beimmediately submitted.used. 9.6.5. Unordered List <UL> ... </UL> Level 0 Thecoordinates of the selected point are measured in pixel units from the upper-left cornerUnordered List element is used to present a list ofthe image, and are returned (alongitems which is typically separated by white space and/or marked by bullets. An unordered list must begin with theother contents of the form) in two name/value pairs. The x-coordinate<UL> tag which issubmitted under the name of the field with .x appended,immediately followed by a <LI> (list item) tag: <UL> <LI>First list item <LI>Second list item <LI>Third list item </UL> 10. Form-based Input Elements Forms are created by placing input fields within paragraphs, preformatted/literal text, and lists. This gives considerable flexibility in designing they- Berners-Lee, Connolly, et. al. Page 40 HTML 2.0 February 8, 1995 coordinate is submitted under the namelayout ofthe field with .y appended. Any VALUE attribute is ignored.forms. Theimage itself is specified by the SRC attribute, exactly as for the Image element. NOTE: Infollowing elements are used to create forms: FORM A form within afuture version of the HTML specification, the IMAGE functionality may be folded into an enhanced SUBMITdocument. INPUT One input field.PASSWORD is the same as the TEXT attribute, except that text is not displayed as it is entered. RADIO is used for attributes that acceptOPTION One option within asingle valueSelect element. SELECT A selection from a finite set ofalternatives.options. TEXTAREA A multi-line input field. Eachradio buttonvariable fieldin the group should be given the same name. Only the selected radio button in the group generates a name/value pair in the submitted data. Radio buttons require an explicit VALUE attribute. RESETisa button that when pressed resets the form's fields to their specified initial values. The labeldefined by an Input, Textarea, or Option element and must have an NAME attribute tobe displayed on the button may be specified just as foridentify its value in theSUBMIT button. SUBMIT is a button thatdata returned whenpressed submitstheform. You canform is submitted. Example of usethe VALUE attribute to provide(a questionnaire form): <H1>Sample Questionnaire</H1> <P>Please fill out this questionnaire: <FORM METHOD="POST" ACTION="http://www.w3.org/sample"> <P>Your name: <INPUT NAME="name" size="48"> <P>Male <INPUT NAME="gender" TYPE=RADIO VALUE="male"> <P>Female <INPUT NAME="gender" TYPE=RADIO VALUE="female"> <P>Number in family: <INPUT NAME="family" TYPE=text> <P>Cities in which you maintain anon- editable labelresidence: <UL> <LI>Kent <INPUT NAME="city" TYPE=checkbox VALUE="kent"> <LI>Miami <INPUT NAME="city" TYPE=checkbox VALUE="miami"> <LI>Other <TEXTAREA NAME="other" cols=48 rows=4></textarea> </UL> Nickname: <INPUT NAME="nickname" SIZE="42"> <P>Thank you for responding tobe displayed onthis questionnaire. <P><INPUT TYPE=SUBMIT> <INPUT TYPE=RESET> </FORM> In thebutton.example above, the <P> and <UL> tags have been used to lay out the text and input fields. Thedefault label is application-specific. If a SUBMIT buttonHTML interpreter ispressed in orderresponsible for handling which field will currently get keyboard input. Many platforms have existing conventions for forms, for example, using Tab and Shift keys tosubmitmove theform,keyboard focus forwards andthat button has a NAME attribute specified, then that button contributes a name/value pairbackwards between fields, and using the Enter key to submit thesubmitted data. Otherwise, aform. In the example, the SUBMIT and RESET buttons are specified explicitly with special purpose fields. The SUBMIT buttonmakes no contribution to the submitted data. TEXTis usedfor a single line text entry fields. Use in conjunction withto e-mail theSIZE and MAXLENGTH attributes. Useform or send its contents to the server as specified by the ACTION attribute, while RESET resets theTextarea element for textfieldswhich can accept multiple lines. VALUE Theto their initialdisplayed value ofvalues. When thefield, if it displays a textual or numerical value; or the value toform consists of a single text field, it may bereturned whenappropriate to leave such buttons out and rely on thefield is selected, if it displays a Boolean value. This attribute is required for radio buttons. 2.15.4 Option <OPTION> Berners-Lee, Connolly, et. al. Page 41 HTML 2.0 February 8, 1995 Level 2Enter key. TheOptionInput elementcan only occur withinis used for aSelect element. It representslarge variety of types of input fields. To let users enter more than onechoice, and can take these attributes: DISABLED Proposed. SELECTED Indicates that this option is initially selected. VALUE When present indicates the value to be returned if this option is chosen. The returned value defaults to the contentsline of text, use theOptionTextarea element. Thecontentsradio button and checkbox types ofthe Option element is presentedinput field can be used to specify multiple choice forms in which every alternative is visible as part of theuserform. An alternative is torepresentuse theoption. ItSelect element which isusedtypically rendered in a more compact fashion as areturned value if the VALUE attribute is not present. 2.15.5 Select <SELECT NAME=... >pull down combo list. 10.1. Form <FORM> ...</SELECT></FORM> Level 2 TheSelectForm elementallows the useris used tochose one ofdelimit aset of alternatives described by textual labels. Every alternative is represented bydata input form. There can be several forms in a single document, but theOption element. Attributes are: ERROR Proposed. MULTIPLEForm element can't be nested. TheMULTIPLEACTION attribute isneeded when users are allowed to make several selections, e.g. <SELECT MULTIPLE>. NAME Specifiesa URI specifying thename that will submitted as a name/value pair. Berners-Lee, Connolly, et. al. Page 42 HTML 2.0 February 8, 1995 SIZE Specifieslocation to which thenumbercontents ofvisible items. If this is greater than one, thentheresultingformcontrol will be a list. The Select elementistypically rendered assubmitted to elicit apull down or pop-up list. For example: <SELECT NAME="flavor"> <OPTION>Vanilla <OPTION>Strawberry <OPTION>Rum and Raisin <OPTION>Peach and Orange </SELECT>response. Ifno option is initially marked as selected, thenthefirst item listedACTION attribute isselected. 2.15.6 Text Area <TEXTAREA> ... </TEXTAREA> Level 2 The Textarea element lets users enter more than one linemissing, the URI oftext. For example: <TEXTAREA NAME="address" ROWS=64 COLS=6> HaL Computer Systems 1315 Dell Avenue Campbell, California 95008 </TEXTAREA> The text up totheend tag (</TEXTAREA>)document itself isused to initialize the field's value. This end tagassumed. The way data isalways required even ifsubmitted varies with thefield is initially blank. When submitting a form, lines in a TEXTAREA should be terminated using CR/LF. In a typical rendering,access protocol of theROWSURI, andCOLS attributes determinewith thevisible dimensionvalues of thefieldMETHOD and ENCTYPE attributes. In general: * the METHOD attribute selects variations incharacters. The field is renderedthe protocol. * the ENCTYPE attribute specifies the format of the submitted data in case the protocol does not impose afixed-width font. HTML user agents should allow textformat itself. When the ACTION attribute is set toextend beyond these limits by scrolling as needed. NOTE: Inan HTTP URL, theinitial designMETHOD attribute must be set to an HTTP method [HTTP]. The default method is GET, although forforms, multi-line text fields were supported bymany applications theInput element with TYPE=TEXT. Unfortunately, this causes problems for Berners-Lee, Connolly, et. al. Page 43 HTML 2.0 February 8, 1995 fields with long text values. SGML's default (Reference Quantity Set) limitsPOST method is preferred. With thelength of attribute literals to only 240 characters. The HTML 2.0 SGML declaration increasesPOST method, thelimit to 1024 characters. 2.16 Character Data Level 0 The characters between HTML tags represent text. A HTML document (including tags and text)ENCTYPE attribute isencoded using the coded character set specified bya media type specifying the"charset" parameterformat of the"text/html" media type. For levels defined in this specification,posted data; the"charset" parameterdefault isrestricted to "US-ASCII" or "ISO-8859-1". ISO-8859-1 encodes a set of characters known as Latin Alphabet No. 1, or simply Latin-1. Latin-1 includes characters from most Western European languages, as well as a number``application/x-www-form-urlencoded''. The submitted contents ofcontrol characters. Latin-1 also includes a non-breaking space, a soft hyphen indicator, 93 graphical characters, 8 unassigned characters, and 25 control characters. Because non-breaking space and soft hyphen indicator are not recognized and interpreted by all HTML user agents, their use is discouraged. There are 58 character positions occupied by control characters. See Section 2.16.2 for details ontheinterpretationform logically consist ofcontrol characters. Because certain special charactersname/value pairs. The names aresubjectusually equal tointerpretation and special processing, information providers and HTML user agent implementors should followtheguidelinesNAME attributes of the various interactive elements inSection 2.16.1. In addition, HTML provides character entity references (see Section 2.17.2) and numerical character references (see Section 2.17.3)the form. NOTE - The names are not guaranteed tofacilitatebe unique keys, nor are theentry and interpretationnames ofcharacters by name and by numerical position. Because certain characters willform elements required to beinterpreted as markup, they mustdistinct. The values encode the user's input to the corresponding interactive elements. Fields with null values may berepresentedomitted from the returned list of name/value pairs, whereas those with non-null values should be included (even if the value was not altered byentity references as described in Section 2.16.3the user). In particular, unselected radio buttons andSection 2.16.4. 2.16.1 Special Characters Certain characters have special meaning in HTML documents. There are two printing characters whichcheckboxes should be excluded from the contents list. 10.2. Input <INPUT> Level 2 The Input element represents a field whose contents may beinterpretededited byan HTML application to have an effectthe user. Attributes of theformatInput element: ALIGN Vertical alignment of thetext: Berners-Lee, Connolly, et. al. Page 44 HTML 2.0 February 8, 1995 Space - Interpreted as a word space (place where a line can be broken) in all contexts exceptimage. For use only with TYPE=IMAGE. The possible values are exactly thePreformatted Text element. - Interpretedsame asa nonbreaking space withinfor thePreformatted TextALIGN attribute of the image element.Hyphen - Interpreted as a hyphen glyph in all contexts - Interpreted as a potential word space by hyphenation engine 2.16.2 Control Characters Control characters are non-printable charactersCHECKED Indicates thatare typically used for communication and device control, as format effectors,a checkbox or radio button is selected. Unselected checkboxes andas information separators. In SGML applications,radio buttons do not return name/value pairs when theuseform is submitted. MAXLENGTH Indicates the maximum number ofcontrolcharactersis limitedthat can be entered into a text field. This can be greater than specified by the SIZE attribute, inorder to maximizewhich case thechancefield will scroll appropriately. The default number ofsuccessful interchange over heterogenous networks and operating systems. In HTML, only three controlcharactersare used: Horizontal Tab (HT, encoded as 9 decimal in US-ASCII and ISO-8859-1), Carriage Return, and Line Feed. Horizontal Tabisinterpreted as a word space in all contexts except preformatted text. Within preformatted text, the tab should be interpreted to shift the horizontal column position tounlimited. NAME Symbolic name used when transferring thenext position whichform's contents. The NAME attribute isa multiple of 8 on the same line; that is, col := (col+8) mod 8. Carriage Returnrequired for most input types andLine Feed are conventionallyis normally used torepresent endprovide a unique identifier for a field, or for a logically related group ofline. For Internet Media Types defined as "text/*",fields. SIZE Specifies thesequence CR LF is usedsize or precision of the field according torepresent an endits type. For example, to specify a field with a visible width ofline. In practice, text/html documents are frequently represented and transmitted using24 characters: INPUT TYPE=text SIZE="24" SRC A URI specifying anend of line convention that depends onimage. For use only with TYPE=IMAGE. TYPE Defines theconventionstype of data thesourcefield accepts. Defaults to free text. Several types of fields can be defined with thedocument; frequently, that representation consists of CR only, LF only,type attribute: CHECKBOX Used for simple Boolean attributes, orCR LF combination. In HTML, endfor attributes that can take multiple values at the same time. The latter is represented by a number ofline in anycheckbox fields each ofits variations is interpreted aswhich has the same name. Each selected checkbox generates aword spaceseparate name/value pair inall contexts except preformatted text. Within preformatted text, HTML interpreting agents should expectthe submitted data, even if this results in duplicate names. The default value for checkboxes is ``on''. HIDDEN No field is presented totreat any ofthethree common representationsuser, but the content ofend-of-line as starting a new line. Berners-Lee, Connolly, et. al. Page 45 HTML 2.0 February 8, 1995 2.16.3 Numeric Character References In additionthe field is sent with the submitted form. This value may be used toany mechanism bytransmit state information about client/server interaction. IMAGE An image field upon whichcharacters mayyou can click with a pointing device, causing the form to berepresented byimmediately submitted. The coordinates of theencodingselected point are measured in pixel units from the upper-left corner of theHTML document, it is possible to explicitly referenceimage, and are returned (along with theprinting charactersother contents of theISO-8859-1 character encoding using a numeric character reference. See Section 2.17.1 for a listform) in two name/value pairs. The x-coordinate is submitted under the name of thecharacters, their namesfield with ``.x'' appended, andinput syntax. Two reasons for using a numeric character reference: -thekeyboard does not provide a key fory-coordinate is submitted under thecharacter, suchname of the field with ``.y'' appended. Any VALUE attribute is ignored. The image itself is specified by the SRC attribute, exactly ason U.S. keyboards which do not provide European charactersfor the Image element. NOTE - In a future version of thecharacterHTML specification, the IMAGE functionality may beinterpreted as SGML coding, suchfolded into an enhanced SUBMIT field. PASSWORD The same as theampersand (&), double quotes ("), the lesser (<) and greater (>) characters Numeric character references are represented in an HTML documentTEXT attribute, except that text is not displayed asSGML entities whose nameit isnumber sign (#) followed byentered. RADIO Used for attributes that accept anumeralsingle value from32-126 and 161-255. The HTML DTD includesanumeric character for each of the printing characters of the ISO-8859-1 encoding, so that one may reference them by number if it is inconvenient to enter them directly: the ampersand (&), double quotes ("), lesser (<) and greater (>) characters 2.16.4 Character Entities In addition, many of the Latin alphabet No. 1set ofprinting characters mayalternatives. Each radio button field in the group should berepresented withingiven thetext of an HTML document by a character entity. See 2.17.2 for a list ofsame name. Only thecharacters, names, input syntax, and descriptions. See 5.2.1 forselected radio button in theSGML entity definitions of "Added Latin 1 for HTML". Two reasons for usinggroup generates acharacter entity: -name/value pair in thekeyboard does not provide a key forsubmitted data. Radio buttons require an explicit VALUE attribute. RESET A button that when pressed resets thecharacter, such asform's fields to their specified initial values. The label to be displayed onU.S. keyboards which do not provide European characters -thecharacterbutton may beinterpreted as SGML coding, suchspecified just as for theampersand (&), double quotes ("), the lesser (<) and greater (>) characters Berners-Lee, Connolly, et. al. Page 46 HTML 2.0 February 8, 1995SUBMIT button. SUBMIT Acharacter entitybutton that when pressed submits the form. You can use the VALUE attribute to provide a non-editable label to be displayed on the button. The default label isrepresented in an HTML document as an SGML entity whose nameapplication-specific. If a SUBMIT button isdefinedpressed in order to submit theHTML DTD. The HTML DTD includesform, and that button has acharacter entityNAME attribute specified, then that button contributes a name/value pair to the submitted data. Otherwise, a SUBMIT button makes no contribution to the submitted data. TEXT Used foreach ofa single line text entry fields. Use in conjunction with theSGML markup charactersSIZE and MAXLENGTH attributes. Use the Textarea element foreachtext fields which can accept multiple lines. VALUE The initial displayed value of theprinting characters in the upper half of Latin-1, so that one may reference them by namefield, if itis inconvenientdisplays a textual or numerical value; or the value toenter them directly:be returned when theampersand (&), double quotes ("), lesser (<) and greater (>) characters Kurt Gödel wasfield is selected, if it displays afamous logicianBoolean value. This attribute is required for radio buttons. 10.3. Option <OPTION> Level 2 The Option element can only occur within a Select element. It represents one choice, andmathematician. NOTE: To ensurecan take these attributes: SELECTED Indicates thata string of charactersthis option isnot interpreted as markup, represent all occurrences of <, >, and & by character or entity references. NOTE: There are SGML features, CDATA and RCDATA, to allow most <, >, and & characters to be entered withoutinitially selected. VALUE When present indicates theuse of entity or character references. Because these features tendvalue to beused and implemented inconsistently, and because they require 8-bit characters to represent non-ASCII characters, they are not used inreturned if thisversionoption is chosen. The returned value defaults to the contents of theHTML DTD. An earlier HTML specification included an ExampleOption element. The contents of the Option element(<XMP>) whose syntaxisnot expressible in SGML. No markup was recognized inside of the Example element exceptpresented to the</XMP> end tag. While HTMLuseragents are encouragedtosupport this idiom, its userepresent the option. It isdeprecated. 2.17 Character Entity Sets The following entity names areusedin HTML, always prefixed by ampersand (&) and followed by a semicolonasshown. They represent particular graphic characters which have special meanings in places ina returned value if themarkup, or mayVALUE attribute is notbe part ofpresent. 10.4. Select <SELECT NAME=... > ... </SELECT> Level 2 The Select element allows thecharacter set availableuser to chose one of a set of alternatives described by textual labels. Every alternative is represented by thewriter. 2.17.1 Numeric and Special Graphic EntitiesOption element. Attributes are: MULTIPLE Thefollowing table lists each ofMULTIPLE attribute is needed when users are allowed to make several selections, e.g. <SELECT MULTIPLE>. NAME Specifies thesupported characters specified inname that will submitted as a name/value pair. SIZE Specifies theNumericnumber of visible items. If this is greater than one, then the resulting form control will be a list. The Select element is typically rendered as a pull down or pop-up list. For example: <SELECT NAME="flavor"> <OPTION>Vanilla <OPTION>Strawberry <OPTION>Rum andSpecial Graphic entity set, along with its name, syntax for use,Raisin <OPTION>Peach anddescription. This listOrange </SELECT> If no option isderived from ISO Standard 8879:1986//ENTITIES Numeric and Special Graphic//EN however HTML does not provide support for the entire entity set. Onlyinitially marked as selected, then theentitiesfirst item listedbelow are Berners-Lee, Connolly, et. al. Page 47 HTML 2.0 February 8, 1995 supported. GLYPH NAME SYNTAX DESCRIPTION < lt < Less than sign > gt > Greateris selected. 10.5. Text Area <TEXTAREA> ... </TEXTAREA> Level 2 The Textarea element lets users enter more thansign & amp & Ampersand " quot " Double quote sign 2.17.2 ISO Latin 1 Character Entitiesone line of text. For example: <TEXTAREA NAME="address" ROWS=64 COLS=6> HaL Computer Systems 1315 Dell Avenue Campbell, California 95008 </TEXTAREA> Thefollowing table lists eachtext up to the end tag (</TEXTAREA>) is used to initialize the field's value. This end tag is always required even if the field is initially blank. When submitting a form, lines in a TEXTAREA should be terminated using CRLF. In a typical rendering, the ROWS and COLS attributes determine the visible dimension of thecharacters specifiedfield in characters. The field is rendered in a fixed-width font. HTML interpreters should allow text to extend beyond these limits by scrolling as needed. NOTE - In theAdded Latin 1 entity set, alonginitial design for forms, multi-line text fields were supported by the Input element withits name, syntaxTYPE=TEXT. Unfortunately, this causes problems foruse, and description.fields with long text values. SGML's default (Reference Quantity Set) limits the length of attribute literals to only 240 characters. The HTML 2.0 SGML declaration increases the limit to 1024 characters. 11. HTML Public Text 11.1. HTML DTD Thislistisderived from ISO Standard 8879:1986//ENTITIES Added Latin 1//EN. HTML supportstheentire entity set. NAME SYNTAX DESCRIPTION Aacute Á Capital A, acute accent Agrave À Capital A, grave accent Acirc  Capital A, circumflex accent Atilde à Capital A, tilde Aring Å Capital A, ring Auml Ä Capital A, dieresis or umlaut mark AElig Æ Capital AE dipthong (ligature) Ccedil Ç Capital C, cedilla Eacute É Capital E, acute accent Egrave È Capital E, grave accent Ecirc Ê Capital E, circumflex accent Euml Ë Capital E, dieresis or umlaut mark Iacute Í Capital I, acute accent Igrave Ì Capital I, grave accent Icirc Î Capital I, circumflex accent Iuml Ï Capital I, dieresis or umlaut mark ETH Ð Capital Eth, Icelandic Ntilde Ñ Capital N, tilde Oacute Ó Capital O, acute accent Ograve Ò Capital O, grave accent Ocirc Ô Capital O, circumflex accent Otilde Õ Capital O, tilde Ouml Ö Capital O, dieresis or umlaut mark Oslash Ø Capital O, slash Uacute Ú Capital U, acute accent Ugrave Ù Capital U, grave accent Ucirc Û Capital U, circumflex accent Uuml Ü Capital U, dieresis or umlaut mark Yacute Ý Capital Y, acute accent THORN Þ Capital THORN, Icelandic szlig ß Small sharp s, German (sz ligature) Berners-Lee, Connolly, et. al. Page 48 HTML 2.0 February 8, 1995 aacute á Small a, acute accent agrave à Small a, grave accent acirc â Small a, circumflex accent atilde ã Small a, tilde aring å Small a, ring auml ä Small a, dieresis or umlaut mark aelig æ Small ae dipthong (ligature) ccedil ç Small c, cedilla eacute é Small e, acute accent egrave è Small e, grave accent ecirc ê Small e, circumflex accent euml ë Small e, dieresis or umlaut mark iacute í Small i, acute accent igrave ì Small i, grave accent icirc î Small i, circumflex accent iuml ï Small i, dieresis or umlaut mark eth ð Small eth, Icelandic ntilde ñ Small n, tilde oacute ó Small o, acute accent ograve ò Small o, grave accent ocirc ô Small o, circumflex accent otilde õ Small o, tilde ouml ö Small o, dieresis or umlaut mark oslash ø Small o, slash uacute ú Small u, acute accent ugrave ù Small u, grave accent ucirc û Small u, circumflex accent uuml ü Small u, dieresis or umlaut mark yacute ý Small y, acute accent thorn þ Small thorn, Icelandic yuml ÿ Small y, dieresis or umlaut mark 2.17.3 Numerical Character References This list, sorted numerically, is derived from ISO-8859-1 8-bit single-byte coded graphic character set: REFERENCE DESCRIPTION � -  Unused 	 Horizontal tab Line feed  -  Unused   Space ! Exclamation mark " Quotation mark # Number sign $ Dollar sign Berners-Lee, Connolly, et. al. Page 49 HTML 2.0 February 8, 1995 % Percent sign & Ampersand ' Apostrophe ( Left parenthesis ) Right parenthesis * Asterisk + Plus sign , Comma - Hyphen . Period (fullstop) / Solidus (slash) 0 - 9 Digits 0-9 : Colon ; Semi-colon < Less than = Equals aign > Greater than ? Question mark @ Commercial at A - Z Letters A-Z [ Left square bracket \ Reverse solidus (backslash) ] Right square bracket ^ Caret _ Horizontal bar ` Acute accent a - z Letters a-z { Left curly brace | Vertical bar } Right curly brace ~ Tilde  -   Unused ¡ Inverted exclamation ¢ Cent sign £ Pound sterling ¤ General currency sign ¥ Yen sign ¦ Broken vertical bar § Section sign ¨ Umlaut (dieresis) © Copyright ª Feminine ordinal Berners-Lee, Connolly, et. al. Page 50 HTML 2.0 February 8, 1995 « Left angle quote, guillemotleft ¬ Not sign ­ Soft hyphen ® Registered trademark ¯ Macron accent ° Degree sign ± Plus or minus ² Superscript two ³ Superscript three ´ Acute accent µ Micro sign ¶ Paragraph sign · Middle dot ¸ Cedilla ¹ Superscript one º Masculine ordinal » Right angle quote, guillemotright ¼ Fraction one-fourth ½ Fraction one-half ¾ Fraction three-fourths ¿ Inverted question mark À Capital A, acute accent Á Capital A, grave accent  Capital A, circumflex accent à Capital A, tilde Ä Capital A, ring Å Capital A, dieresis or umlaut mark Æ Capital AE dipthong (ligature) Ç Capital C, cedilla È Capital E, acute accent É Capital E, grave accent Ê Capital E, circumflex accent Ë Capital E, dieresis or umlaut mark Ì Capital I, acute accent Í Capital I, grave accent Î Capital I, circumflex accent Ï Capital I, dieresis or umlaut mark Ð Capital Eth, Icelandic Ñ Capital N, tilde Ò Capital O, acute accent Ó Capital O, grave accent Ô Capital O, circumflex accent Õ Capital O, tilde Ö Capital O, dieresis or umlaut mark × Multiply sign Ø Capital O, slash Ù Capital U, acute accent Berners-Lee, Connolly, et. al. Page 51 HTML 2.0 February 8, 1995 Ú Capital U, grave accent Û Capital U, circumflex accent Ü Capital U, dieresis or umlaut mark Ý Capital Y, acute accent Þ Capital THORN, Icelandic ß Small sharp s, German (sz ligature) à Small a, acute accent á Small a, grave accent â Small a, circumflex accent ã Small a, tilde ä Small a, dieresis or umlaut mark å Small a, ring æ Small ae dipthong (ligature) ç Small c, cedilla è Small e, acute accent é Small e, grave accent ê Small e, circumflex accent ë Small e, dieresis or umlaut mark ì Small i, acute accent í Small i, grave accent î Small i, circumflex accent ï Small i, dieresis or umlaut mark ð Small eth, Icelandic ñ Small n, tilde ò Small o, acute accent ó Small o, grave accent ô Small o, circumflex accent õ Small o, tilde ö Small o, dieresis or umlaut mark ÷ Division sign ø Small o, slash ù Small u, acute accent ú Small u, grave accent û Small u, circumflex accent ü Small u, dieresis or umlaut mark ý Small y, acute accent þ Small thorn, Icelandic ÿ Small y, dieresis or umlaut mark 3. Security Considerations Anchors, embedded images, and all other elements which contain URIs as parameters may causeDocument Type Definition for theURI to be dereferenced in response to user input. In this case,HyperText Markup Language. <!-- html.dtd Document Type Definition for thesecurity considerationsHyperText Markup Language (HTML DTD) 5 $Id: html.dtd,v 1.25 1995/03/29 18:53:13 connolly Exp $ Author: Daniel W. Connolly <connolly@w3.org> See Also: html.decl, html-0.dtd, html-1.dtd 10 http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html --> <!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0//EN" 15 -- Typical usage: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> <html> 20 ... </html> -- > 25 <!--============ Feature Test Entities ========================--> <!ENTITY % HTML.Recommended "IGNORE" -- Certain features of theURI specification apply. Berners-Lee, Connolly, et. al. Page 52 HTML 2.0 February 8, 1995 Documentslanguage are necessary for 30 compatibility with widespread usage, but they maybe constructed whose visible contents misleadcompromise thereader to followstructural integrity of alink to unsuitable or offensive material. 4. Obsolete and Proposed Features 4.1 Obsolete Featuresdocument. Thissection describes elementsfeature test entity enables a more prescriptive document type definition thatare no longer parteliminates those features. 35 --> <![ %HTML.Recommended [ <!ENTITY % HTML.Deprecated "IGNORE"> ]]> 40 <!ENTITY % HTML.Deprecated "INCLUDE" -- Certain features ofHTML. Client implementors should implement these obsolete elementsthe language are necessary for compatibility withpreviousearlier versions of theHTML specification. 4.1.1 Comment The Comment element is used to delimit unneeded text and comments. The Comment element has been introduced in some HTML applicationsspecification, butshould be replaced by the SGML comment feature in new HTML user agents (see Section 2.6.5). 4.1.2 Highlighted Phrase The Highlighted Phrase element (<HP>) shouldthey tend to beignored if not implemented. This element has been replaced by more meaningful elements (see Section 2.9). Example of use: <HP1>first highlighted phrase</HP1>non highlighted text<HP2>second highlighted phrase</HP2> etc. 4.1.3 Plain Text <PLAINTEXT> The Plain Text element isused an implemented inconsistently, 45 and their use is deprecated. This feature test entity enables a document type definition that eliminates these features. --> 50 <!ENTITY % HTML.Highlighting "INCLUDE" -- Use this feature test entity toterminates the HTMLvalidate that a document uses no highlighting tags, which may be ignored on minimal implementations. --> 55 <!ENTITY % HTML.Forms "INCLUDE" -- Use this feature test entityandtoindicatevalidate thatwhat follows is not SGMLa document contains no forms, whichdoesmay notrequire parsing. Instead,be supported in minimal implementations 60 --> <!--============== Imported Names ==============================--> <!ENTITY % Content-Type "CDATA" 65 -- meaning anoldinternet media type (aka MIME content type, as per RFC1521) --> <!ENTITY % HTTP-Method "GET | POST" 70 -- as per HTTPconvention specified that what followed was an ASCII (MIME "text/plain") body. Its presence is an optimization. There is no closing tag. Example of use: <PLAINTEXT> 0001 Thisspecification, in progress --> <!ENTITY % URI "CDATA" -- The term URI means a CDATA attribute 75 whose value isline onea Uniform Resource Identifier, as defined by "Universal Resource Identifiers" by Tim Berners-Lee aka RFC 1630 80 Note that CDATA attributes are limited by the LITLEN capacity (1024 in the current version of html.decl), so that URIs in HTML have along listing Berners-Lee, Connolly, et. al. Page 53bounded length. --> 85 <!--========= DTD "Macros" =====================--> <!ENTITY % heading "H1|H2|H3|H4|H5|H6"> 90 <!ENTITY % list " UL | OL | DIR | MENU " > <!--======= Character mnemonic entities =================--> 95 <!ENTITY % ISOlat1 PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML"> %ISOlat1; 100 <!ENTITY amp CDATA "&" -- ampersand --> <!ENTITY gt CDATA ">" -- greater than --> <!ENTITY lt CDATA "<" -- less than --> <!ENTITY quot CDATA """ -- double quote --> 105 <!--========= SGML Document Access (SDA) Parameter Entities =====--> <!-- HTML 2.0February 8, 1995 0002 file from <ANY@HOST.INC.COM> which is sent 4.1.4 Example and Listing <XMP> ... </XMP> and <LISTING> ... </LISTING> The Example element and Listing element have been replaced by the Preformatted Text element. These styles allow textcontains SGML Document Access (SDA) fixed attributes in support offixed-width characterseasy transformation tobe embedded absolutely as is intothedocument. The syntax is: <LISTING> ... </LISTING> or <XMP> ... </XMP> The text between these tags is typically rendered in a monospaced font so that any formatting doneInternational Committee 110 for Accessible Document Design (ICADD) DTD "-//EC-USA-CDA/ICADD//DTD ICADD22//EN". ICADD applications are designed to support usable access to structured information bycharacter spacing on successive lines will be maintained. Between the openingprint-impaired individuals through Braille, large print andclosing tags:voice synthesis. For more information on 115 SDA & ICADD: -The text may contain anyISOLatin-1 printable characters, expect12083:1993, Annex A.8, Facilities forthe end tag opener. The ExampleBraille, large print andListing elements have historically used specifications which do not conform to SGML. Specifically,computer voice - ICADD ListServ <ICADD%ASUACAD.BITNET@ARIZVM1.ccit.arizona.edu> 120 - Usenet news group bit.listserv.easi - Recording for the Blind, +1 800 221 4792 --> <!ENTITY % SDAFORM "SDAFORM CDATA #FIXED" 125 -- one to one mapping --> <!ENTITY % SDARULE "SDARULE CDATA #FIXED" -- context-sensitive mapping --> <!ENTITY % SDAPREF "SDAPREF CDATA #FIXED" -- generated text prefix --> 130 <!ENTITY % SDASUFF "SDASUFF CDATA #FIXED" -- generated text suffix --> <!ENTITY % SDASUSP "SDASUSP NAME #FIXED" -- suspend transform process --> 135 <!--========== Text Markup =====================--> <![ %HTML.Highlighting [ 140 <!ENTITY % font " TT | B | I "> <!ENTITY % phrase "EM | STRONG | CODE | SAMP | KBD | VAR | CITE "> <!ENTITY % textmay contain ISO Latin printable characters, including the tag opener, as long it they does not contain the closing tag in full."#PCDATA | A | IMG | BR | %phrase | %font"> 145 <!ELEMENT (%font;|%phrase) -SGML does not support this form. HTML user agents may vary on how they interpret other tags within Example and Listing elements.-Line boundaries within the(%text)*> <!ATTLIST ( TT | CODE | SAMP | KBD | VAR ) %SDAFORM; "Lit" > 150 <!ATTLIST ( B | STRONG ) %SDAFORM; "B" > <!ATTLIST ( I | EM | CITE ) %SDAFORM; "It" 155 > <!-- <TT> Typewriter text --> <!-- <B> Bold text --> <!-- <I> Italic text --> 160 <!-- <EM> Emphasized phrase --> <!-- <STRONG> Strong emphais --> <!-- <CODE> Source code phrase --> <!-- <SAMP> Sample textare rendered as a move to the beginning of the next line, except for one immediately following a start tag or immediately preceding an end tag. - The horizontal tab character must be interpreted as the smallest positive nonzero number of spaces which will leave the number of characters so far on the line as a multiple of 8. Its use is not Berners-Lee, Connolly, et. al. Page 54 HTML 2.0 February 8, 1995 recommended. The Listing element is rendered so that at least 132 characters fit on a line. The Example element is rendered to that at least 80 characters fit on a line but is otherwise identical to the Listing element. 4.2 Proposed Features This section describes proposed HTML elements and entities that are not currently supported under HTML Levels 0, 1,or2, but may be supported in the future. 4.2.1 Defining Instance <DFN> ... </DFN> The Defining Instance element indicates the defining instance of a term. The typical rendering is boldcharacters --> 165 <!-- <KBD> Keyboard phrase, e.g. user input --> <!-- <VAR> Variable phrase orbold italic. This element is not widely supported. 4.2.2 Special Characters To indicate special characters, HTML uses entitysubstituable --> <!-- <CITE> Name ornumeric representations. Additional character presentations are proposed: CHARACTER REPRESENTATION Non-breaking space Soft-hyphen ­ Registered ® Copyright © 4.2.3 Strike <STRIKE> ... </STRIKE> The Strike element is proposed to indicate strikethrough, a font style in which a horizontal line appears through characters. This element is not widely supported. 4.2.4 Underline <U> ... </U> The Underline element is proposed to indicate that the text should be rendered as underlined. This proposed tag is not supported by all HTML user agents. Berners-Lee, Connolly, et. al. Page 55 HTML 2.0 February 8, 1995 Exampletitle ofuse: Thecited work --> <!ENTITY % pre.content "#PCDATA | A | HR | BR | %font | %phrase"> 170 ]]> <!ENTITY % text<U>shown here</U> is rendered in the document as underlined. 5. HTML Document Type Definitions 5.1 SGML Declaration for HTML This is the SGML Declaration for HyperText Markup Language (HTML) as used by the World Wide Web (WWW) application: <!SGML "ISO 8879:1986" -- SGML Declaration for HyperText"#PCDATA | A | IMG | BR"> 175 <!ELEMENT BR - O EMPTY> <!ATTLIST BR %SDAPREF; "&#RE;" > 180 <!-- <BR> Line break --> <!--========= Link MarkupLanguage (HTML).======================--> 185 <![ %HTML.Recommended [ <!ENTITY % linkName "ID"> ]]> <!ENTITY % linkName "CDATA"> 190 <!ENTITY % linkType "NAME" --CHARSET BASESET "ISO 646:1983//CHARSET International Reference Version (IRV)//ESC 2/5 4/0" DESCSET 0 9 UNUSED 9 2 9 11 2 UNUSED 13 1 13 14 18 UNUSED 32 95 32 127 1 UNUSED BASESET "ISO Registration Number 100//CHARSET ECMA-94 Right Parta list ofLatin Alphabet Nr. 1//ESC 2/13 4/1" DESCSET 128 32 UNUSED 160 96 32 CAPACITY SGMLREF TOTALCAP 150000 GRPCAP 150000 SCOPE DOCUMENT SYNTAX SHUNCHAR CONTROLS 0these will be specified at a later date --> <!ENTITY % linkExtraAttributes 195 "REL %linkType #IMPLIED REV %linkType #IMPLIED URN CDATA #IMPLIED TITLE CDATA #IMPLIED METHODS NAMES #IMPLIED 200 "> <![ %HTML.Recommended [ <!ENTITY % A.content "(%text)*" -- <H1><a name="xxx">Heading</a></H1> 205 is preferred to <a name="xxx"><H1>Heading</H1></a> --> ]]> 210 <!ENTITY % A.content "(%heading|%text)*"> <!ELEMENT A - - %A.content -(A)> <!ATTLIST A HREF %URI #IMPLIED 215 NAME %linkName #IMPLIED %linkExtraAttributes; %SDAPREF; "<Anchor: #AttList>" > <!-- <A> Anchor; source/destination of link --> 220 <!-- <A NAME="..."> Name of this anchor --> <!-- <A HREF="..."> Address of link destination --> <!-- <A URN="..."> Permanent address of destination --> <!-- <A REL=...> Relationship to destination --> <!-- <A REV=...> Relationship of destination to this --> 225 <!-- <A TITLE="..."> Title of destination (advisory) --> <!-- <A METHODS="..."> Operations on destination (advisory) --> <!--========== Images ==========================--> 230 <!ELEMENT IMG - O EMPTY> <!ATTLIST IMG SRC %URI; #REQUIRED ALT CDATA #IMPLIED 235 ALIGN (top|middle|bottom) #IMPLIED ISMAP (ISMAP) #IMPLIED %SDAPREF; "<Fig><?SDATrans Img: #AttList>#AttVal(Alt)</Fig>" > 240 <!-- <IMG> Image; icon, glyph or illustration --> <!-- <IMG SRC="..."> Address of image object --> <!-- <IMG ALT="..."> Textual alternative --> <!-- <IMG ALIGN=...> Position relative to text --> <!-- <IMG ISMAP> Each pixel can be a link --> 245 <!--========== Paragraphs=======================--> <!ELEMENT P - O (%text)*> <!ATTLIST P 250 %SDAFORM; "Para" > <!-- <P> Paragraph --> 255 <!--========== Headings, Titles, Sections ===============--> <!ELEMENT HR - O EMPTY> <!ATTLIST HR 260 %SDAPREF; "&#RE;&#RE;" > <!-- <HR> Horizontal rule --> 265 <!ELEMENT ( %heading ) - - (%text;)*> <!ATTLIST H1 %SDAFORM; "H1" > <!ATTLIST H2 270 %SDAFORM; "H2" > <!ATTLIST H3 %SDAFORM; "H3" > 275 <!ATTLIST H4 %SDAFORM; "H4" > <!ATTLIST H5 %SDAFORM; "H5" 280 > <!ATTLIST H6 %SDAFORM; "H6" > 285 <!-- <H1> Heading, level 1 --> <!-- <H2> Heading, level 2 --> <!-- <H3> Heading, level 3 --> <!-- <H4> Heading, level 4 --> <!-- <H5> Heading, level 5 --> 290 <!-- <H6> Heading, level 67 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 127 BASESET "ISO 646:1983//CHARSET International Reference Version (IRV)//ESC 2/5 4/0" DESCSET 0 128 0 FUNCTION Berners-Lee, Connolly, et. al. Page 56 HTML 2.0 February 8, 1995 RE 13 RS 10 SPACE 32 TAB SEPCHAR 9 NAMING LCNMSTRT "" UCNMSTRT "" LCNMCHAR ".-" UCNMCHAR ".-" NAMECASE GENERAL YES ENTITY NO DELIM GENERAL SGMLREF SHORTREF SGMLREF NAMES SGMLREF QUANTITY SGMLREF ATTSPLEN 2100 LITLEN 1024 NAMELEN 72 -- somewhat arbitrary; taken from internet--> <!--========== Text Flows ======================--> 295 <![ %HTML.Forms [ <!ENTITY % block.forms "BLOCKQUOTE | FORM | ISINDEX"> ]]> <!ENTITY % block.forms "BLOCKQUOTE"> 300 <![ %HTML.Deprecated [ <!ENTITY % preformatted "PRE | XMP | LISTING"> ]]> 305 <!ENTITY % preformatted "PRE"> <!ENTITY % block "P | %list | DL | %preformatted | %block.forms"> 310 <!ENTITY % flow "(%text|%block)*"> <!ENTITY % pre.content "#PCDATA | A | HR | BR"> <!ELEMENT PRE - - (%pre.content)*> 315 <!ATTLIST PRE WIDTH NUMBER #implied %SDAFORM; "Lit" > 320 <!-- <PRE> Preformatted text --> <!-- <PRE WIDTH=...> Maximum characters per linelength conventions -- PILEN 1024 TAGLEN 2100 FEATURES MINIMIZE DATATAG NO OMITTAG YES RANK NO SHORTTAG YES LINK SIMPLE NO IMPLICIT NO EXPLICIT NO OTHER CONCUR NO SUBDOC NO FORMAL YES APPINFO "SDA"--> <![ %HTML.Deprecated [ 325 <!ENTITY % literal "CDATA" --conforming SGMLhistorical, non-conforming parsing mode where the only markup signal is the end tag in full --> 330 <!ELEMENT (XMP|LISTING) - - %literal> <!ATTLIST XMP %SDAFORM; "Lit" %SDAPREF; "Example:&#RE;" 335 > <!ATTLIST LISTING %SDAFORM; "Lit" %SDAPREF; "Listing:&#RE;" > 340 <!-- <XMP> Example section --> <!-- <LISTING> Computer listing --> <!ELEMENT PLAINTEXT - O %literal> 345 <!-- <PLAINTEXT> Plain text passage --> <!ATTLIST PLAINTEXT %SDAFORM; "Lit" > 350 ]]> <!--========== Lists ==================--> 355 <!ELEMENT DL - - (DT | DD)+> <!ATTLIST DL COMPACT (COMPACT) #IMPLIED %SDAFORM; "List" %SDAPREF; "Definition List:" 360 > <!ELEMENT DT - O (%text)*> <!ATTLIST DT %SDAFORM; "Term" 365 > <!ELEMENT DD - O %flow> <!ATTLIST DD %SDAFORM; "LItem" 370 > <!-- <DL> Definition list, or glossary --> <!-- <DL COMPACT> Compact style list --> <!-- <DT> Term in definition list --> 375 <!-- <DD> Definition of term --> <!ELEMENT (OL|UL) - - (LI)+> <!ATTLIST OL COMPACT (COMPACT) #IMPLIED 380 %SDAFORM; "List" > <!ATTLIST UL COMPACT (COMPACT) #IMPLIED %SDAFORM; "List" 385 > <!-- <UL> Unordered list --> <!-- <UL COMPACT> Compact list style --> <!-- <OL> Ordered, or numbered list --> <!-- <OL COMPACT> Compact list style --> 390 <!ELEMENT (DIR|MENU) - - (LI)+ -(%block)> <!ATTLIST DIR COMPACT (COMPACT) #IMPLIED 395 %SDAFORM; "List" %SDAPREF; "<LHead>Directory</LHead>" > <!ATTLIST MENU COMPACT (COMPACT) #IMPLIED 400 %SDAFORM; "List" %SDAPREF; "<LHead>Menu</LHead>" > <!-- <DIR> Directory list --> 405 <!-- <DIR COMPACT> Compact list style --> <!-- <MENU> Menu list --> <!-- <MENU COMPACT> Compact list style --> <!ELEMENT LI - O %flow> 410 <!ATTLIST LI %SDAFORM; "LItem" > <!-- <LI> List item --> 415 <!--========== DocumentAccess applicationBody ===================--> <![ %HTML.Recommended [ <!ENTITY % body.content "(%heading|%block|HR|ADDRESS|IMG)*" 420 -- <h1>Heading</h1> <p>Text ... is preferred to <h1>Heading</h1> Text ... 425 --> ]]> <!ENTITY % body.content "(%heading | %text | %block | HR | ADDRESS)*"> 430 <!ELEMENT BODY O O %body.content> <!-- <BODY> Document body --> 435 <!ELEMENT BLOCKQUOTE - - %body.content> <!ATTLIST BLOCKQUOTE %SDAFORM; "BQ" > 440 <!-- <BLOCKQUOTE> Quoted passage --> <!ELEMENT ADDRESS - - (%text|P)*> <!ATTLIST ADDRESS %SDAFORM; "Lit" 445 %SDAPREF; "Address:&#RE;" > <!-- <ADDRESS> Address, signature, or byline --> 450 <!--======= Forms ====================--> <![ %HTML.Forms [ 455 <!ELEMENT FORM - - %body.content -(FORM) +(INPUT|SELECT|TEXTAREA)> <!ATTLIST FORM ACTION %URI #IMPLIED METHOD (%HTTP-Method) GET ENCTYPE %Content-Type; "application/x-www-form-urlencoded" 460 %SDAPREF; "<Para>Form:</Para>" %SDASUFF; "<Para>Form End.</Para>" > <!-- <FORM> Fill-out or data-entry form --> 465 <!-- <FORM ACTION="..."> Address for completed form --> <!-- <FORM METHOD=...> Method of submitting form --> <!-- <FORM ENCTYPE="..."> Representation of form data --> <!ENTITY % InputType "(TEXT | PASSWORD | CHECKBOX | 470 RADIO | SUBMIT | RESET | IMAGE | HIDDEN )"> <!ELEMENT INPUT - O EMPTY> <!ATTLIST INPUT TYPE %InputType TEXT 475 NAME CDATA #IMPLIED VALUE CDATA #IMPLIED SRC %URI #IMPLIED CHECKED (CHECKED) #IMPLIED SIZE CDATA #IMPLIED 480 MAXLENGTH NUMBER #IMPLIED ALIGN (top|middle|bottom) #IMPLIED %SDAPREF; "Input: " > 485 <!--$Id: html.decl,v 1.13 1995/02/08 08:29:33 connolly Exp $ Author: Daniel W. Connolly <connolly@hal.com> See also: http://www.hal.com/%7Econnolly/html-spec http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html<INPUT> Form input datum -->5.1.1 Sample SGML Open Style Entity Catalog for HTML Berners-Lee, Connolly, et. al. Page 57 HTML 2.0 February 8, 1995 The SGML standard describes an "entity manager" as the portion or component<!-- <INPUT TYPE=...> Type ofan SGML system that maps SGML entities into the actual storage model (e.g., the file system). The standard itself does not define a particular mapping methodology or notation. To assist the interoperability among various SGML tools and systems, the SGML Open consortium has passed a technical resolution that defines a format for an application-independent entity catalog that maps external identifiers and/or entity names to file names. Each entry in the catalog associates a storage object identifier (such as a file name) with information about the external entity that appears in the SGML document. In addition to entries that associate public identifiers, a catalog entry can associate an entity name withinput interaction --> <!-- <INPUT NAME=...> Name of form datum --> <!-- <INPUT VALUE="..."> Default/initial/selected value --> <!-- <INPUT SRC="..."> Address of image --> 490 <!-- <INPUT CHECKED> Initial state is "on" --> <!-- <INPUT SIZE=...> Field size hint --> <!-- <INPUT MAXLENGTH=...> Data length maximum --> <!-- <INPUT ALIGN=...> Image alignment --> 495 <!ELEMENT SELECT - - (OPTION+) -(INPUT|SELECT|TEXTAREA)> <!ATTLIST SELECT NAME CDATA #REQUIRED SIZE NUMBER #IMPLIED MULTIPLE (MULTIPLE) #IMPLIED 500 %SDAFORM; "List" %SDAPREF; "<LHead>Select #AttVal(Multiple)</LHead>" > 505 <!-- <SELECT> Selection of option(s) --> <!-- <SELECT NAME=...> Name of form datum --> <!-- <SELECT SIZE=...> Options displayed at astorage object indentifier. For example, the following are possible catalog entries: PUBLIC "ISO 8879:1986//ENTITIES Added Latin 1//EN" "iso-lat1.gml" PUBLIC "-//ACME DTD Writers//DTD General Report//EN" report.dtd ENTITY "graph1" "graphics\graph1.cgm" In particular, the following shows entries relevant to HTML. -- catalog: SGML Open style entity catalogtime --> <!-- <SELECT MULTIPLE> Multiple selections allowed --> 510 <!ELEMENT OPTION - O (#PCDATA)*> <!ATTLIST OPTION SELECTED (SELECTED) #IMPLIED VALUE CDATA #IMPLIED %SDAFORM; "LItem" 515 %SDAPREF; "Option: #AttVal(Value) #AttVal(Selected)" > <!-- <OPTION> A selection option --> 520 <!-- <OPTION SELECTED> Initial state --> <!-- <OPTION VALUE="..."> Form datum value forHTML -- -- $Id: catalog,v 1.1 1994/10/07 21:35:07 connolly Exp $ -- -- Ways to refer to Level 2: most general to most specific -- PUBLIC "-//IETF//DTD HTML//EN" html.dtd PUBLIC "-//IETF//DTD HTML//EN//2.0" html.dtd PUBLIC "-//IETF//DTD HTML Level 2//EN" html.dtd PUBLIC "-//IETF//DTD HTML Level 2//EN//2.0" html.dtdthis option--> <!ELEMENT TEXTAREA - - (#PCDATA)* -(INPUT|SELECT|TEXTAREA)> <!ATTLIST TEXTAREA 525 NAME CDATA #REQUIRED ROWS NUMBER #REQUIRED COLS NUMBER #REQUIRED %SDAFORM; "Para" %SDAPREF; "Input Text --Ways to refer#AttVal(Name): " 530 > <!-- <TEXTAREA> An area for text input --> <!-- <TEXTAREA NAME=...> Name of form datum --> <!-- <TEXTAREA ROWS=...> Height of area --> 535 <!-- <TEXTAREA COLS=...> Width of area --> ]]> 540 <!--======= Document Head ======================--> <![ %HTML.Recommended [ <!ENTITY % head.extra "META* & LINK*"> ]]> 545 <!ENTITY % head.extra "NEXTID? & META* & LINK*"> <!ENTITY % head.content "TITLE & ISINDEX? & BASE? & (%head.extra)"> 550 <!ELEMENT HEAD O O (%head.content)> <!-- <HEAD> Document head --> 555 <!ELEMENT TITLE - - (#PCDATA)*> <!ATTLIST TITLE %SDAFORM; "Ti" > <!-- <TITLE> Title of document --> 560 <!ELEMENT LINK - O EMPTY> <!ATTLIST LINK HREF %URI #REQUIRED %linkExtraAttributes; 565 %SDAPREF; "Linked toLevel 1: most general: #AttVal (TITLE) (URN) (HREF)>" > <!-- <LINK> Link from this document --> <!-- <LINK HREF="..."> Address of link destination --> <!-- <LINK URN="..."> Lasting name of destination --> 570 <!-- <LINK REL=...> Relationship tomost specific -- PUBLIC "-//IETF//DTD HTML Level 1//EN" html-1.dtd PUBLIC "-//IETF//DTD HTML Level 1//EN//2.0" html-1.dtd -- Waysdestination --> <!-- <LINK REV=...> Relationship of destination toreferthis --> <!-- <LINK TITLE="..."> Title of destination (advisory) --> <!-- <LINK METHODS="..."> Operations allowed (advisory) --> 575 <!ELEMENT ISINDEX - O EMPTY> <!ATTLIST ISINDEX %SDAPREF; "<Para>[Document is indexed/searchable.]</Para>"> 580 <!-- <ISINDEX> Document is a searchable index --> <!ELEMENT BASE - O EMPTY> <!ATTLIST BASE HREF %URI; #REQUIRED > 585 <!-- <BASE> Base context document --> <!-- <BASE HREF="..."> Address for this document --> <!ELEMENT NEXTID - O EMPTY> 590 <!ATTLIST NEXTID N %linkName #REQUIRED > <!-- <NEXTID> Next ID toLevel 0: most generaluse for link name --> <!-- <NEXTID N=...> Next ID tomost specific -- PUBLIC "-//IETF//DTDuse for link name --> 595 <!ELEMENT META - O EMPTY> <!ATTLIST META HTTP-EQUIV NAME #IMPLIED NAME NAME #IMPLIED 600 CONTENT CDATA #REQUIRED > <!-- <META> Generic Metainformation --> <!-- <META HTTP-EQUIV=...> HTTP response header name --> <!-- <META NAME=...> Metainformation name --> 605 <!-- <META CONTENT="..."> Associated information --> <!--======= Document Structure =================--> <![ %HTML.Deprecated [ 610 <!ENTITY % html.content "HEAD, BODY, PLAINTEXT?"> ]]> <!ENTITY % html.content "HEAD, BODY"> <!ELEMENT HTML O O (%html.content)> 615 <!ENTITY % version.attr "VERSION CDATA #FIXED '%HTML.Version;'"> <!ATTLIST HTMLLevel 0//EN" html-0.dtd PUBLIC "-//IETF//DTD%version.attr; %SDAFORM; "Book" 620 > <!-- <HTML> HTMLLevel 0//EN//2.0" html-0.dtd -- ISO latin 1 entity setDocument --> 11.2. SGML Declaration for HTML This is the SGML Declaration for HyperText Markup Language (HTML) as used by the World Wide Web (WWW) application: <!SGML "ISO 8879:1986" -- SGML Declaration for HyperText Markup Language (HTML). 5 -- CHARSET BASESET "ISO 646:1983//CHARSET International Reference Version 10 (IRV)//ESC 2/5 4/0" DESCSET 0 9 UNUSED 9 2 9 11 2 UNUSED 13 1 13 15 14 18 UNUSED 32 95 32 127 1 UNUSED BASESET "ISO Registration Number 100//CHARSET ECMA-94 Right Part of 20 Latin Alphabet Nr. 1//ESC 2/13 4/1" DESCSET 128 32 UNUSED 160 96 32 25 CAPACITY SGMLREF TOTALCAP 150000 GRPCAP 150000 ENTCAP 150000 30 SCOPE DOCUMENT SYNTAX SHUNCHAR CONTROLS 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 127 BASESET "ISO 646:1983//CHARSET 35 International Reference Version (IRV)//ESC 2/5 4/0" DESCSET 0 128 0 FUNCTION RE 13 40 RS 10 SPACE 32 TAB SEPCHAR 9 45 NAMING LCNMSTRT "" UCNMSTRT "" LCNMCHAR ".-" UCNMCHAR ".-" NAMECASE GENERAL YES 50 ENTITY NO DELIM GENERAL SGMLREF SHORTREF SGMLREF NAMES SGMLREF QUANTITY SGMLREF 55 ATTSPLEN 2100 LITLEN 1024 NAMELEN 72 -- somewhat arbitrary; taken from internet line length conventions -- PILEN 1024 60 TAGLEN 2100 GRPGTCNT 150 GRPCNT 64 FEATURES 65 MINIMIZE DATATAG NO OMITTAG YES RANK NO SHORTTAG YES 70 LINK SIMPLE NO IMPLICIT NO EXPLICIT NO OTHER 75 CONCUR NO SUBDOC NO FORMAL YES APPINFO "SDA" --PUBLIC "-//IETF//ENTITIES Added Latin 1//EN" ISOlat1.sgml 5.2 HTML DTD This is theconforming SGML DocumentType Definition for the HyperText Markup Language (HTML DTD): Berners-Lee, Connolly, et. al. Page 58 HTML 2.0 February 8, 1995Access application -- 80 > <!--html.dtd Document Type Definition for the HyperText Markup Language (HTML DTD)$Id:html.dtd,v 1.24 1995/02/06 21:28:45html.decl,v 1.15 1995/05/06 01:44:47 connolly Exp $ Author: Daniel W. Connolly <connolly@hal.com> 85 SeeAlso: html.decl, html-0.dtd, html-1.dtd http://www.hal.com/%7Econnolly/html-spec/index.html http://info.cern.ch/hypertext/WWW/MarkUp2/MarkUp.htmlalso: http://www.hal.com/%7Econnolly/html-spec http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html --><!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0//EN" -- Typical usage: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> <html> ... </html> -- > <!--============ Feature Test Entities ========================--> <!ENTITY % HTML.Recommended "IGNORE" -- Certain features of the language are necessary11.3. Sample SGML Open Entity Catalog forcompatibility with widespread usage, but they may compromiseHTML The SGML standard describes an ``entity manager'' as thestructural integrityportion or component ofa document. This feature test entity enables a more prescriptive document type definitionan SGML system thateliminates those features. --> <![ %HTML.Recommended [ <!ENTITY % HTML.Deprecated "IGNORE"> ]]> <!ENTITY % HTML.Deprecated "INCLUDE" -- Certain features ofmaps SGML entities into thelanguage are necessary for compatibility with earlier versions ofactual storage model (e.g., thespecification, but they tend to be used an implemented inconsistently, and their use is deprecated. This feature test entity enables a document type definition that eliminates these features. --> Berners-Lee, Connolly, et. al. Page 59 HTML 2.0 February 8, 1995 <!ENTITY % HTML.Highlighting "INCLUDE" -- Use this feature test entity to validate thatfile system). The standard itself does not define adocument uses no highlighting tags, which may be ignored on minimal implementations. --> <!ENTITY % HTML.Forms "INCLUDE" -- Use this feature test entity to validateparticular mapping methodology or notation. To assist the interoperability among various SGML tools and systems, the SGML Open consortium has passed a technical resolution that defines adocument contains no forms, which may not be supported in minimal implementations --> <!--============== Imported Names ==============================--> <!ENTITY % Content-Type "CDATA" -- meaningformat for aninternet media type (aka MIME content type, as per RFC1521) --> <!ENTITY % HTTP-Method "GET | POST" -- as per HTTP specification,application- independent entity catalog that maps external identifiers and/or entity names to file names. Each entry inprogress --> <!ENTITY % URI "CDATA" -- The term URI means a CDATA attribute whose value isthe catalog associates aUniform Resource Identifier,storage object identifier (such asdefined by "Universal Resource Identifiers" by Tim Berners-Lee aka RFC 1630 Note that CDATA attributes are limited bya file name) with information about theLITLEN capacity (1024external entity that appears in thecurrent version of html.decl), soSGML document. In addition to entries thatURIs in HTML haveassociate public identifiers, abounded length. --> <!--========= DTD "Macros" =====================--> <!ENTITY % heading "H1|H2|H3|H4|H5|H6"> <!ENTITY % list " UL | OL | DIR | MENU " > <!--======= Character mnemonic entities =================--> <!ENTITY % ISOlat1catalog entry can associate an entity name with a storage object indentifier. For example, the following are possible catalog entries: -- catalog: SGML Open style entity catalog for HTML -- -- $Id: catalog,v 1.2 1994/11/30 23:45:18 connolly Exp $ -- -- Ways to refer to Level 2: most general to most specific -- 5 PUBLIC "-//IETF//DTD HTML//EN" html.dtd PUBLIC "-//IETF//DTD HTML 2.0//EN" html.dtd PUBLIC "-//IETF//DTD HTML Level 2//EN" html.dtd PUBLIC"ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML"> %ISOlat1; Berners-Lee, Connolly, et. al. Page 60"-//IETF//DTD HTML 2.0February 8, 1995 <!ENTITY amp CDATA "&"Level 2//EN" html.dtd 10 --ampersand --> <!ENTITY gt CDATA ">"Ways to refer to Level 1: most general to most specific --greater than --> <!ENTITY lt CDATA "<"PUBLIC "-//IETF//DTD HTML Level 1//EN" html-1.dtd PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN" html-1.dtd --less than --> <!ENTITY quot CDATA """Ways to refer to Level 0: most general to most specific --double quote --> <!--========= SGML Document Access (SDA) Parameter Entities =====--> <!--15 PUBLIC "-//IETF//DTD HTML Level 0//EN" html-0.dtd PUBLIC "-//IETF//DTD HTML 2.0contains SGML Document Access (SDA) fixed attributes in support of easy transformationLevel 0//EN" html-0.dtd -- Ways tothe International Committee for Accessible Document Design (ICADD) DTD "-//EC-USA-CDA/ICADD//DTD ICADD22//EN". ICADD applications are designedrefer tosupport usable accessStrict Level 2: most general tostructured information by print-impaired individuals through Braille, large print and voice synthesis. For more information on SDAmost specific \ &ICADD: - ISO 12083:1993, Annex A.8, Facilities for Braille, large print and computer voice - ICADD ListServ <ICADD%ASUACAD.BITNET@ARIZVM1.ccit.arizona.edu> - Usenet news group bit.listserv.easi - Recording for the Blind, +1 800 221 4792 --> <!ENTITY % SDAFORM "SDAFORM CDATA #FIXED" -- one to one mapping --> <!ENTITY % SDARULE "SDARULE CDATA #FIXED" -- context-sensitive mapping --> <!ENTITY % SDAPREF "SDAPREF CDATA #FIXED"--generated text prefix --> <!ENTITY % SDASUFF "SDASUFF CDATA #FIXED"20 PUBLIC "-//IETF//DTD HTML Strict//EN" html-s.dtd PUBLIC "-//IETF//DTD HTML 2.0 Strict//EN" html-s.dtd PUBLIC "-//IETF//DTD HTML Strict Level 2//EN" html-s.dtd PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 2//EN" html-s.dtd 25 --generated text suffix --> <!ENTITY % SDASUSP "SDASUSP NAME #FIXED"Ways to refer to Strict Level 1: most general to most specific \ & --suspend transform process --> <!--========== Text Markup =====================--> <![ %HTML.Highlighting [ <!ENTITY % font " TT | B | I "> <!ENTITY % phrase "EM | STRONG | CODE | SAMP | KBD | VAR | CITE "> <!ENTITY % text "#PCDATA | A | IMG | BR | %phrase | %font"> <!ELEMENT (%font;|%phrase) - - (%text)*> <!ATTLIST ( TT | CODE | SAMP | KBD | VAR ) %SDAFORM; "Lit" > Berners-Lee, Connolly, et. al. Page 61PUBLIC "-//IETF//DTD HTML Strict Level 1//EN" html-1s.dtd PUBLIC "-//IETF//DTD HTML 2.0February 8, 1995 <!ATTLIST ( B | STRONG ) %SDAFORM; "B" > <!ATTLIST ( I | EM | CITE ) %SDAFORM; "It" > <!-- <TT> Typewriter text --> <!-- <B> Bold text --> <!-- <I> Italic text --> <!-- <EM> Emphasized phrase --> <!-- <STRONG> Strong emphais --> <!-- <CODE> Source code phrase --> <!-- <SAMP> Sample text or characters --> <!-- <KBD> Keyboard phrase, e.g. user input --> <!-- <VAR> Variable phrase or substituable --> <!-- <CITE> Name or title of cited work --> <!ENTITY % pre.content "#PCDATA | A | HR | BR | %font | %phrase"> ]]> <!ENTITY % text "#PCDATA | A | IMG | BR"> <!ELEMENT BR - O EMPTY> <!ATTLIST BR %SDAPREF; "&#RE;" > <!-- <BR> Line break --> <!--========= Link Markup ======================--> <![ %HTML.Recommended [ <!ENTITY % linkName "ID"> ]]> <!ENTITY % linkName "CDATA"> <!ENTITY % linkType "NAME"Strict Level 1//EN" html-1s.dtd -- Ways to refer to Strict Level 0: most general to most specific \ & -- 30 PUBLIC "-//IETF//DTD HTML Strict Level 0//EN" html-0s.dtd PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 0//EN" html-0s.dtd --aISO latin 1 entity set for HTML -- PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML" ISOlat1.sg\ & ml 11.4. Character Entity Sets The HTML DTD defines the following entities. They represent particular graphic characters which have special meanings in places in the markup, or may not be part of the character set available to the writer. 11.4.1. Numeric and Special Graphic Entity Set The following table lists each of the characters included from the Numeric and Special Graphic entity set, along with its name, syntax for use, and description. This list is derived from `ISO Standard 8879:1986//ENTITIES Numeric and Special Graphic//EN'. However, HTML does not include for the entire entity set -- only the entities listed below are included. GLYPH NAME SYNTAX DESCRIPTION < lt < Less than sign > gt > Greater than sign & amp & Ampersand " quot " Double quote sign 11.4.2. ISO Latin 1 Character Entity Set The following public text lists each ofthese will bethe characters specifiedat a later date --> <!ENTITY % linkExtraAttributes "REL %linkType #IMPLIED REV %linkType #IMPLIED URN CDATA #IMPLIED TITLE CDATA #IMPLIED METHODS NAMES #IMPLIED Berners-Lee, Connolly, et. al. Page 62in the Added Latin 1 entity set, along with its name, syntax for use, and description. This list is derived from ISO Standard 8879:1986//ENTITIES Added Latin 1//EN. HTML2.0 February 8, 1995 "> <![ %HTML.Recommended [ <!ENTITY % A.content "(%text)*" -- <H1><a name="xxx">Heading</a></H1>includes the entire entity set. <!-- (C) International Organization for Standardization 1986 Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice ispreferred to <a name="xxx"><H1>Heading</H1></a>included in all copies. 5 -->]]><!-- Character entity set. Typical invocation: <!ENTITY %A.content "(%heading|%text)*"> <!ELEMENT A - - %A.content -(A)> <!ATTLIST A HREF %URI #IMPLIED NAME %linkName #IMPLIED %linkExtraAttributes; %SDAPREF; "<Anchor: #AttList>" > <!-- <A> Anchor; source/destination of linkISOlat1 PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML"> %ISOlat1; 10 --> <!--<A NAME="..."> Name of this anchorModified for use in HTML $Id: ISOlat1.sgml,v 1.2 1994/11/30 23:45:12 connolly Exp $ --><!-- <A HREF="..."> Address of link destination<!ENTITY AElig CDATA "Æ" -- capital AE diphthong (ligature) --><!-- <A URN="..."> Permanent address of destination<!ENTITY Aacute CDATA "Á" -- capital A, acute accent --><!-- <A REL=...> Relationship to destination15 <!ENTITY Acirc CDATA "Â" -- capital A, circumflex accent --><!-- <A REV=...> Relationship of destination to this<!ENTITY Agrave CDATA "À" -- capital A, grave accent --><!-- <A TITLE="..."> Title of destination (advisory)<!ENTITY Aring CDATA "Å" -- capital A, ring --><!-- <A METHODS="..."> Operations on destination (advisory)<!ENTITY Atilde CDATA "Ã" -- capital A, tilde --><!--========== Images ==========================--> <!ELEMENT IMG - O EMPTY> <!ATTLIST IMG SRC %URI; #REQUIRED ALT<!ENTITY Auml CDATA#IMPLIED ALIGN (top|middle|bottom) #IMPLIED ISMAP (ISMAP) #IMPLIED %SDAPREF; "<Fig><?SDATrans Img: #AttList>#AttVal(Alt)</Fig>" > <!-- <IMG> Image; icon, glyph"Ä" -- capital A, dieresis orillustration --> <!-- <IMG SRC="..."> Address of image objectumlaut mark --><!-- <IMG ALT="..."> Textual alternative20 <!ENTITY Ccedil CDATA "Ç" -- capital C, cedilla --><!-- <IMG ALIGN=...> Position relative to text<!ENTITY ETH CDATA "Ð" -- capital Eth, Icelandic --><!-- <IMG ISMAP> Each pixel can be a link<!ENTITY Eacute CDATA "É" -- capital E, acute accent --><!--========== Paragraphs=======================--> <!ELEMENT P - O (%text)*> <!ATTLIST P Berners-Lee, Connolly, et. al. Page 63 HTML 2.0 February 8, 1995 %SDAFORM; "Para" > <!-- <P> Paragraph<!ENTITY Ecirc CDATA "Ê" -- capital E, circumflex accent --><!--========== Headings, Titles, Sections ===============--> <!ELEMENT HR - O EMPTY> <!ATTLIST HR %SDAPREF; "&#RE;&#RE;" > <!-- <HR> Horizontal rule<!ENTITY Egrave CDATA "È" -- capital E, grave accent --><!ELEMENT ( %heading ) - - (%text;)*> <!ATTLIST H1 %SDAFORM; "H1" > <!ATTLIST H2 %SDAFORM; "H2" > <!ATTLIST H3 %SDAFORM; "H3" > <!ATTLIST H4 %SDAFORM; "H4" > <!ATTLIST H5 %SDAFORM; "H5" > <!ATTLIST H6 %SDAFORM; "H6" > <!-- <H1> Heading, level 125 <!ENTITY Euml CDATA "Ë" -- capital E, dieresis or umlaut mark --><!-- <H2> Heading, level 2<!ENTITY Iacute CDATA "Í" -- capital I, acute accent --><!-- <H3> Heading, level 3<!ENTITY Icirc CDATA "Î" -- capital I, circumflex accent --><!-- <H4> Heading, level 4<!ENTITY Igrave CDATA "Ì" -- capital I, grave accent --><!-- <H5> Heading, level 5<!ENTITY Iuml CDATA "Ï" -- capital I, dieresis or umlaut mark --><!-- <H6> Heading, level 630 <!ENTITY Ntilde CDATA "Ñ" -- capital N, tilde --><!--========== Text Flows ======================--> <![ %HTML.Forms [<!ENTITY% block.forms "BLOCKQUOTE | FORM | ISINDEX"> ]]>Oacute CDATA "Ó" -- capital O, acute accent --> <!ENTITY% block.forms "BLOCKQUOTE"> Berners-Lee, Connolly, et. al. Page 64 HTML 2.0 February 8, 1995 <![ %HTML.Deprecated [Ocirc CDATA "Ô" -- capital O, circumflex accent --> <!ENTITY% preformatted "PRE | XMP | LISTING"> ]]>Ograve CDATA "Ò" -- capital O, grave accent --> <!ENTITY Oslash CDATA "Ø" -- capital O, slash --> 35 <!ENTITY% preformatted "PRE">Otilde CDATA "Õ" -- capital O, tilde --> <!ENTITY% block "P | %list | DL | %preformatted | %block.forms">Ouml CDATA "Ö" -- capital O, dieresis or umlaut mark --> <!ENTITY% flow "(%text|%block)*">THORN CDATA "Þ" -- capital THORN, Icelandic --> <!ENTITY% pre.content "#PCDATA | A | HR | BR"> <!ELEMENT PRE - - (%pre.content)*> <!ATTLIST PRE WIDTH NUMBER #implied %SDAFORM; "Lit" > <!-- <PRE> Preformatted textUacute CDATA "Ú" -- capital U, acute accent --><!-- <PRE WIDTH=...> Maximum characters per line<!ENTITY Ucirc CDATA "Û" -- capital U, circumflex accent --><![ %HTML.Deprecated [40 <!ENTITY% literal "CDATA"Ugrave CDATA "Ù" --historical, non-conforming parsing mode where the only markup signal is the end tag in fullcapital U, grave accent --><!ELEMENT (XMP|LISTING) - - %literal> <!ATTLIST XMP %SDAFORM; "Lit" %SDAPREF; "Example:&#RE;" > <!ATTLIST LISTING %SDAFORM; "Lit" %SDAPREF; "Listing:&#RE;" > <!-- <XMP> Example section<!ENTITY Uuml CDATA "Ü" -- capital U, dieresis or umlaut mark --><!-- <LISTING> Computer listing<!ENTITY Yacute CDATA "Ý" -- capital Y, acute accent --><!ELEMENT PLAINTEXT - O %literal> <!-- <PLAINTEXT> Plain text passage<!ENTITY aacute CDATA "á" -- small a, acute accent --><!ATTLIST PLAINTEXT %SDAFORM; "Lit" > Berners-Lee, Connolly, et. al. Page 65 HTML 2.0 February 8, 1995 ]]> <!--========== Lists ==================--> <!ELEMENT DL - - (DT | DD)+> <!ATTLIST DL COMPACT (COMPACT) #IMPLIED %SDAFORM; "List" %SDAPREF; "Definition List:" > <!ELEMENT DT - O (%text)*> <!ATTLIST DT %SDAFORM; "Term" > <!ELEMENT DD - O %flow> <!ATTLIST DD %SDAFORM; "LItem" > <!-- <DL> Definition list,<!ENTITY acirc CDATA "â" -- small a, circumflex accent --> 45 <!ENTITY aelig CDATA "æ" -- small ae diphthong (ligature) --> <!ENTITY agrave CDATA "à" -- small a, grave accent --> <!ENTITY aring CDATA "å" -- small a, ring --> <!ENTITY atilde CDATA "ã" -- small a, tilde --> <!ENTITY auml CDATA "ä" -- small a, dieresis orglossaryumlaut mark --><!-- <DL COMPACT> Compact style list50 <!ENTITY ccedil CDATA "ç" -- small c, cedilla --><!-- <DT> Term in definition list<!ENTITY eacute CDATA "é" -- small e, acute accent --><!-- <DD> Definition of term<!ENTITY ecirc CDATA "ê" -- small e, circumflex accent --><!ELEMENT (OL|UL) - - (LI)+> <!ATTLIST OL COMPACT (COMPACT) #IMPLIED %SDAFORM; "List" > <!ATTLIST UL COMPACT (COMPACT) #IMPLIED %SDAFORM; "List" > <!-- <UL> Unordered list<!ENTITY egrave CDATA "è" -- small e, grave accent --><!-- <UL COMPACT> Compact list style<!ENTITY eth CDATA "ð" -- small eth, Icelandic --><!-- <OL> Ordered,55 <!ENTITY euml CDATA "ë" -- small e, dieresis ornumbered listumlaut mark --><!-- <OL COMPACT> Compact list style<!ENTITY iacute CDATA "í" -- small i, acute accent --><!ELEMENT (DIR|MENU) - - (LI)+ -(%block)> <!ATTLIST DIR COMPACT (COMPACT) #IMPLIED %SDAFORM; "List" %SDAPREF; "<LHead>Directory</LHead>" > <!ATTLIST MENU COMPACT (COMPACT) #IMPLIED Berners-Lee, Connolly, et. al. Page 66 HTML 2.0 February 8, 1995 %SDAFORM; "List" %SDAPREF; "<LHead>Menu</LHead>" > <!-- <DIR> Directory list<!ENTITY icirc CDATA "î" -- small i, circumflex accent --><!-- <DIR COMPACT> Compact list style<!ENTITY igrave CDATA "ì" -- small i, grave accent --><!-- <MENU> Menu list<!ENTITY iuml CDATA "ï" -- small i, dieresis or umlaut mark --> 60 <!ENTITY ntilde CDATA "ñ" -- small n, tilde --><!-- <MENU COMPACT> Compact list style<!ENTITY oacute CDATA "ó" -- small o, acute accent --><!ELEMENT LI - O %flow> <!ATTLIST LI %SDAFORM; "LItem" > <!-- <LI> List item<!ENTITY ocirc CDATA "ô" -- small o, circumflex accent --><!--========== Document Body ===================--> <![ %HTML.Recommended [<!ENTITY% body.content "(%heading|%block|HR|ADDRESS|IMG)*"ograve CDATA "ò" --<h1>Heading</h1> <p>Text ... is preferred to <h1>Heading</h1> Text ...small o, grave accent -->]]><!ENTITY% body.content "(%heading | %text | %block | HR | ADDRESS)*"> <!ELEMENT BODY O O %body.content> <!-- <BODY> Document bodyoslash CDATA "ø" -- small o, slash --><!ELEMENT BLOCKQUOTE - - %body.content> <!ATTLIST BLOCKQUOTE %SDAFORM; "BQ" > <!-- <BLOCKQUOTE> Quoted passage65 <!ENTITY otilde CDATA "õ" -- small o, tilde --><!ELEMENT ADDRESS - - (%text|P)*> <!ATTLIST ADDRESS %SDAFORM; "Lit" %SDAPREF; "Address:&#RE;" > <!-- <ADDRESS> Address, signature,<!ENTITY ouml CDATA "ö" -- small o, dieresis orbylineumlaut mark -->Berners-Lee, Connolly, et. al. Page 67 HTML 2.0 February 8, 1995 <!--======= Forms ====================--> <![ %HTML.Forms [ <!ELEMENT FORM - - %body.content -(FORM) +(INPUT|SELECT|TEXTAREA)> <!ATTLIST FORM ACTION %URI #IMPLIED METHOD (%HTTP-Method) GET ENCTYPE %Content-Type; "application/x-www-form-urlencoded" %SDAPREF; "<Para>Form:</Para>" %SDASUFF; "<Para>Form End.</Para>" > <!-- <FORM> Fill-out or data-entry form<!ENTITY szlig CDATA "ß" -- small sharp s, German (sz ligature) --><!-- <FORM ACTION="..."> Address for completed form<!ENTITY thorn CDATA "þ" -- small thorn, Icelandic --><!-- <FORM METHOD=...> Method of submitting form<!ENTITY uacute CDATA "ú" -- small u, acute accent --><!-- <FORM ENCTYPE="..."> Representation of form data70 <!ENTITY ucirc CDATA "û" -- small u, circumflex accent --> <!ENTITY ugrave CDATA "ù" -- small u, grave accent --> <!ENTITY% InputType "(TEXT | PASSWORD | CHECKBOX | RADIO | SUBMIT | RESET | IMAGE | HIDDEN )"> <!ELEMENT INPUT - O EMPTY> <!ATTLIST INPUT TYPE %InputType TEXT NAMEuuml CDATA#IMPLIED VALUE"ü" -- small u, dieresis or umlaut mark --> <!ENTITY yacute CDATA#IMPLIED SRC %URI #IMPLIED CHECKED (CHECKED) #IMPLIED SIZE"ý" -- small y, acute accent --> <!ENTITY yuml CDATA#IMPLIED MAXLENGTH NUMBER #IMPLIED ALIGN (top|middle|bottom) #IMPLIED %SDAPREF; "Input: " > <!-- <INPUT> Form input datum"ÿ" -- small y, dieresis or umlaut mark --><!-- <INPUT TYPE=...> Type12. Glossary character An atom ofinput interaction --> <!-- <INPUT NAME=...> Nameinformation, for example a letter or a digit. Graphic characters have associated glyphs, where as control characters have associated processing semantics. character encoding scheme A function whose domain is the set ofform datum --> <!-- <INPUT VALUE="..."> Default/initial/selected value --> <!-- <INPUT SRC="..."> Addresssequences ofimage --> <!-- <INPUT CHECKED> Initial stateoctets, and whose range is"on" --> <!-- <INPUT SIZE=...> Field size hint --> <!-- <INPUT MAXLENGTH=...> Data length maximum --> <!-- <INPUT ALIGN=...> Image alignment --> <!ELEMENT SELECT - - (OPTION+) -(INPUT|SELECT|TEXTAREA)> <!ATTLIST SELECT NAME CDATA #REQUIRED SIZE NUMBER #IMPLIED MULTIPLE (MULTIPLE) #IMPLIED Berners-Lee, Connolly, et. al. Page 68 HTML 2.0 February 8, 1995 %SDAFORM; "List" %SDAPREF; "<LHead>Select #AttVal(Multiple)</LHead>" > <!-- <SELECT> Selectionthe set of sequences of characters from a character repertoire; that is, a sequence of octets and a character encoding scheme determines a sequence of characters. character repertoire A finite set of characters; e.g. the range of a coded character set. code position An integer. A coded character set and a code position from its domain determine a character. coded character set A function whose domain is a subset ofoption(s) --> <!-- <SELECT NAME=...> Namethe integers and whose range is a character repertoire. That is, for some set of integers (usually of the formdatum --> <!-- <SELECT SIZE=...> Options displayed at{0, 1, 2, ..., N} ), atime --> <!-- <SELECT MULTIPLE> Multiple selections allowed --> <!ELEMENT OPTION - O (#PCDATA)*> <!ATTLIST OPTION SELECTED (SELECTED) #IMPLIED VALUE CDATA #IMPLIED %SDAFORM; "LItem" %SDAPREF; "Option: #AttVal(Value) #AttVal(Selected)" > <!-- <OPTION>coded character set and an integer in that set determine a character. Conversely, a character and a coded character set determine the character's code position (or, in rare cases, a few code positions). conforming HTML user agent Aselection option --> <!-- <OPTION SELECTED> Initial state --> <!-- <OPTION VALUE="..."> Form datum value foruser agent that conforms to thisoption--> <!ELEMENT TEXTAREA - - (#PCDATA)* -(INPUT|SELECT|TEXTAREA)> <!ATTLIST TEXTAREA NAME CDATA #REQUIRED ROWS NUMBER #REQUIRED COLS NUMBER #REQUIRED %SDAFORM; "Para" %SDAPREF; "Input Text -- #AttVal(Name): " > <!-- <TEXTAREA> An area for text input --> <!-- <TEXTAREA NAME=...> Namespecification in its processing ofform datum --> <!-- <TEXTAREA ROWS=...> Heightthe Internet Media Type `text/html; version=2.0'. data character Characters other than markup, which make up the content of elements. document character set a coded character set whose range includes all characters used in a document. Every SGML document has exactly one document character set. Numeric character references are resolved via the document character set. DTD document type definition. Rules that apply SGML to the markup of documents of a particular type, including a set of element and entity declarations. [SGML] element A component of the hierarchical structure defined by a document type definition; it is identified in a document instance by descriptive markup, sually a start-tag and end-tag. [SGML] end-tag Descriptive markup that identifies the end ofarea --> <!-- <TEXTAREA COLS=...> Widthan element. [SGML] entity data with an associated notation or interpretation; for example, a sequence ofarea --> ]]> <!--======= Document Head ======================--> <![ %HTML.Recommended [ <!ENTITY % head.extra "META* & LINK*"> ]]> <!ENTITY % head.extra "NEXTID? & META* & LINK*"> <!ENTITY % head.content "TITLE & ISINDEX? & BASE? & (%head.extra)"> Berners-Lee, Connolly, et. al. Page 69octets associated with an Internet Media Type.[SGML] HTML2.0 February 8, 1995 <!ELEMENT HEAD O O (%head.content)> <!-- <HEAD> Document head --> <!ELEMENT TITLE - - (#PCDATA)*> <!ATTLIST TITLE %SDAFORM; "Ti" > <!-- <TITLE> Titledocument An SGML document conforming to this document type definition. markup Syntactically delimited characters added to the data of a document--> <!ELEMENT LINK - O EMPTY> <!ATTLIST LINK HREF %URI #REQUIRED %linkExtraAttributes; %SDAPREF; "Linkedto: #AttVal (TITLE) (URN) (HREF)>" > <!-- <LINK> Link fromrepresent its structure. There are four different kinds of markup: descriptive markup (tags), references, markup declarations, and processing instructions.[SGML] may A document or user interface is conforming whether this statement applies or not. message entity a head and body. The head is a collection of name/value fields, and the body is a sequence of octets. The head defines the content type and content transfer encoding of the body. [MIME] must Documents or user agents in conflict with this statement are not conforming. SGML document--> <!-- <LINK HREF="..."> AddressA sequence oflink destination --> <!-- <LINK URN="..."> Lasting namecharacters organized physically as a set ofdestination --> <!-- <LINK REL=...> Relationship to destination --> <!-- <LINK REV=...> Relationshipentities and logically into a hierarchy of elements. An SGML document consists ofdestination to this --> <!-- <LINK TITLE="..."> Titledata characters and markup; the markup describes the structure ofdestination (advisory) --> <!-- <LINK METHODS="..."> Operations allowed (advisory) --> <!ELEMENT ISINDEX - O EMPTY> <!ATTLIST ISINDEX %SDAPREF; "<Para>[Document is indexed/searchable.]</Para>"> <!-- <ISINDEX> Document isthe information and an instance of that structure.[SGML] shall If asearchable index --> <!ELEMENT BASE - O EMPTY> <!ATTLIST BASE HREF %URI; #REQUIRED > <!-- <BASE> Base contextdocument--> <!-- <BASE HREF="..."> Address foror user agent conflicts with thisdocument --> <!ELEMENT NEXTID - O EMPTY> <!ATTLIST NEXTID N %linkName #REQUIRED > <!-- <NEXTID> Next IDstatement, it does not conform touse for link name --> <!-- <NEXTID N=...> Next IDthis specification. should If a document or user agent conflicts with this statement, undesirable results may occur in practice even though it conforms touse for link name --> <!ELEMENT META - O EMPTY> <!ATTLIST META HTTP-EQUIV NAME #IMPLIED NAME NAME #IMPLIED Berners-Lee, Connolly, et. al. Page 70 HTML 2.0 February 8, 1995 CONTENT CDATA #REQUIRED > <!-- <META> Generic Metainformation --> <!-- <META HTTP-EQUIV=...> HTTP response header name --> <!-- <META HTTP-EQUIV=...> Metainformation name --> <!-- <META CONTENT="..."> Associated information --> <!--======= Document Structure =================--> <![ %HTML.Deprecated [ <!ENTITY % html.content "HEAD, BODY, PLAINTEXT?"> ]]> <!ENTITY % html.content "HEAD, BODY"> <!ELEMENT HTML O O (%html.content)> <!ENTITY % version.attr "VERSION CDATA #FIXED '%HTML.Version;'"> <!ATTLIST HTML %version.attr; %SDAFORM; "Book" > <!-- <HTML> HTML Document --> 5.2.1 ISO Latin 1 Definitions for HTML <!-- (C) International Organizationthis specification. start-tag Descriptive markup that identifies the start of an element and specifies its generic identifier and attributes. [SGML] syntax-reference character set A coded character set whose range includes all characters used forStandardization 1986 Permissionmarkup; e.g. name characters and delimiter characters. tag Markup that delimits an element. A tag includes a name which refers tocopyan element declaration inanythe DTD, and may include attributes.[SGML] text entity A finite sequence of characters. A text entity typically takes the form of a sequence of octets with some associated character encoding scheme, transmitted over the network or stored in a file.[SGML] typical Typical processing isgranteddescribed foruse with conforming SGML systemsmany elements. This is not a mandatory part of the specification but is given as guidance for designers andapplicationsto help explain the uses for which the elements were intended. URI A Universal Resource Identifier is a formatted string that serves asdefinedan identifier for a resource, typcally on the Internet. URIs are used inISO 8879:1986, provided this noticeHTML to identify the destination of hypertext links, the source of in-line images, and the object of form actions. URIs in common use include Uniform Resource Locators (URLs)[URL] and Relative URLs[RELURL]. user agent A component of a distributed system that presents an interface and processes requests on behalf of a user; for example, a www browser or a mail user agent. WWW The World-Wide Web isincludeda hypertext-based, distributed information system created by researchers at CERN in Switzerland. Users may create, edit or browse hypertext documents. `http://www.w3.org/' 13. Bibliography [URI] T. Berners-Lee. ``Universal Resource Identifiers in WWW: A Unifying Syntax for the Expression of Names and Addresses of Objects on the Network as used in the World- Wide Web.'' RFC 1630, CERN, June 1994. [URL] T. Berners-Lee, L. Masinter, and M. McCahill. ``Uniform Resource Locators (URL).'' RFC 1738, CERN, Xerox PARC, University of Minnesota, October 1994. [HTTP] T. Berners-Lee, R. T. Fielding, and H. Frystyk Nielsen. ``Hypertext Transfer Protocol - HTTP/1.0.'' Work in Progress (draft-ietf-http-v10-spec-00.ps), MIT, UC Irvine, CERN, March 1995. [MIME] N. Borenstein and N. Freed. ``MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies.'' RFC 1521, Bellcore, Innosoft, September 1993. [RELURL] R. T. Fielding. ``Relative Uniform Resource Locators.'' Work inall copies. --> <!--Progress (draft-ietf-uri- relative-url-06.txt), UC Irvine, March 1995. [GOLD90] C. F. Goldfarb. ``The SGML Handbook.'' Y. Rubinsky, Ed., Oxford University Press, 1990. [IMEDIA] J. Postel. ``Media Type Registration Procedure.'' RFC 1590, USC/ISI, March 1994. [IANA] J. Reynolds and J. Postel. ``Assigned Numbers.'' STD 2, RFC 1700, USC/ISI, October 1994. [SQ91] SoftQuad. ``The SGML Primer.'' 3rd ed., SoftQuad Inc., 1991. [US-ASCII] US-ASCII. Coded Characterentity set. Typical invocation: <!ENTITY % ISOlat1 PUBLIC "-//IETF//ENTITIES Added Latin 1 for HTML//EN"> %ISOlat1; --> <!-- ModifiedSet - 7-Bit American Standard Code foruse in HTML $Id: ISOlat1.sgml,v 1.1 1994/09/24 14:06:34 connolly Exp $ --> <!ENTITY AElig CDATA "Æ" -- capital AE diphthong (ligature) --> <!ENTITY Aacute CDATA "Á" -- capital A, acute accent --> <!ENTITY Acirc CDATA "Â" -- capital A, circumflex accent --> <!ENTITY Agrave CDATA "À" -- capital A, grave accent --> <!ENTITY Aring CDATA "Å"Information Interchange. Standard ANSI X3.4-1986, ANSI, 1986. [ISO-8859-1] ISO 8859. International Standard --capital A, ring --> <!ENTITY Atilde CDATA "Ã"Information Processing --capital A, tilde --> <!ENTITY Auml CDATA "Ä"8-bit Single-Byte Coded Graphic Character Sets --capital A, dieresis or umlautPart 1: Latin Alphabet No. 1, ISO 8859-1:1987. Part 2: Latin alphabet No. 2, ISO 8859-2, 1987. Part 3: Latin alphabet No. 3, ISO 8859-3, 1988. Part 4: Latin alphabet No. 4, ISO 8859-4, 1988. Part 5: Latin/Cyrillic alphabet, ISO 8859-5, 1988. Part 6: Latin/Arabic alphabet, ISO 8859-6, 1987. Part 7: Latin/Greek alphabet, ISO 8859-7, 1987. Part 8: Latin/Hebrew alphabet, ISO 8859-8, 1988. Part 9: Latin alphabet No. 5, ISO 8859-9, 1990. [SGML] ISO 8879. Information Processing - Text and Office Systems - Standard Generalized Markup Language (SGML), 1986. 14. Appendices These appendices are provided for informational reasons only - they do not form a part of the HTML specification. 14.1. The ISO-8859-1 Coded Character Set This list, sorted numerically, is derived from ISO-8859-1 8-bit single-byte coded graphic character set: REFERENCE DESCRIPTION � -  Unused 	 Horizontal tab Line feed  -  Unused   Space ! Exclamation mark " Quotation mark # Number sign $ Dollar sign % Percent sign & Ampersand ' Apostrophe ( Left parenthesis ) Right parenthesis * Asterisk + Plus sign , Comma - Hyphen . Period (fullstop) / Solidus (slash) 0 - 9 Digits 0-9 : Colon ; Semi-colon < Less than = Equals sign > Greater than ? Question mark--> <!ENTITY Ccedil CDATA "Ç" -- capital C, cedilla --> <!ENTITY ETH CDATA "Ð" -- capital Eth, Icelandic --> <!ENTITY Eacute CDATA "É" -- capital E, acute accent --> <!ENTITY Ecirc CDATA "Ê" -- capital E, circumflex@ Commercial at A - Z Letters A-Z [ Left square bracket \ Reverse solidus (backslash) ] Right square bracket ^ Caret _ Horizontal bar (underscore) ` Acute accent--> <!ENTITY Egrave CDATA "È" -- capital E, gravea - z Letters a-z { Left curly brace | Vertical bar } Right curly brace ~ Tilde  -   Unused ¡ Inverted exclamation ¢ Cent sign £ Pound sterling ¤ General currency sign ¥ Yen sign ¦ Broken vertical bar § Section sign ¨ Umlaut (dieresis) © Copyright ª Feminine ordinal « Left angle quote, guillemotleft ¬ Not sign ­ Soft hyphen ® Registered trademark ¯ Macron accent--> Berners-Lee, Connolly, et. al. Page 71 HTML 2.0 February 8, 1995 <!ENTITY Euml CDATA "Ë" -- capital E, dieresis° Degree sign ± Plus orumlaut mark --> <!ENTITY Iacute CDATA "Í" -- capital I, acute accent --> <!ENTITY Icirc CDATA "Î" -- capital I, circumflexminus ² Superscript two ³ Superscript three ´ Acute accent--> <!ENTITY Igrave CDATA "Ì" -- capital I,µ Micro sign ¶ Paragraph sign · Middle dot ¸ Cedilla ¹ Superscript one º Masculine ordinal » Right angle quote, guillemotright ¼ Fraction one-fourth ½ Fraction one-half ¾ Fraction three-fourths ¿ Inverted question mark À Capital A, grave accent--> <!ENTITY Iuml CDATA "Ï" -- capital I, dieresis or umlaut mark --> <!ENTITY Ntilde CDATA "Ñ" -- capital N, tilde --> <!ENTITY Oacute CDATA "Ó" -- capital O,Á Capital A, acute accent--> <!ENTITY Ocirc CDATA "Ô" -- capital O, Capital A, circumflex accent--> <!ENTITY Ograve CDATA "Ò" -- capital O, grave accent --> <!ENTITY Oslash CDATA "Ø" -- capital O, slash --> <!ENTITY Otilde CDATA "Õ" -- capital O,à Capital A, tilde--> <!ENTITY Ouml CDATA "Ö" -- capital O,Ä Capital A, dieresis or umlaut mark--> <!ENTITY THORN CDATA "Þ" -- capital THORN, Icelandic --> <!ENTITY Uacute CDATA "Ú" -- capital U,Å Capital A, ring Æ Capital AE dipthong (ligature) Ç Capital C, cedilla È Capital E, grave accent É Capital E, acute accent--> <!ENTITY Ucirc CDATA "Û" -- capital U,Ê Capital E, circumflex accent--> <!ENTITY Ugrave CDATA "Ù" -- capital U, grave accent --> <!ENTITY Uuml CDATA "Ü" -- capital U,Ë Capital E, dieresis or umlaut mark--> <!ENTITY Yacute CDATA "Ý" -- capital Y, acuteÌ Capital I, grave accent--> <!ENTITY aacute CDATA "á" -- small a,Í Capital I, acute accent--> <!ENTITY acirc CDATA "â" -- small a, circumflex accent --> <!ENTITY aelig CDATA "æ" -- small ae diphthong (ligature) --> <!ENTITY agrave CDATA "à" -- small a, grave accent --> <!ENTITY aring CDATA "å" -- small a, ring --> <!ENTITY atilde CDATA "ã" -- small a, tilde --> <!ENTITY auml CDATA "ä" -- small a,Î Capital I, circumflex accent Ï Capital I, dieresis or umlaut mark--> <!ENTITY ccedil CDATA "ç" -- small c, cedilla --> <!ENTITY eacute CDATA "é" -- small e,Ð Capital Eth, Icelandic Ñ Capital N, tilde Ò Capital O, grave accent Ó Capital O, acute accent--> <!ENTITY ecirc CDATA "ê" -- small e,Ô Capital O, circumflex accent--> <!ENTITY egrave CDATA "è" -- small e, grave accent --> <!ENTITY eth CDATA "ð" -- small eth, Icelandic --> <!ENTITY euml CDATA "ë" -- small e,Õ Capital O, tilde Ö Capital O, dieresis or umlaut mark--> <!ENTITY iacute CDATA "í" -- small i,× Multiply sign Ø Capital O, slash Ù Capital U, grave accent Ú Capital U, acute accent--> <!ENTITY icirc CDATA "î" -- small i,Û Capital U, circumflex accent--> <!ENTITY igrave CDATA "ì" -- small i, grave accent --> <!ENTITY iuml CDATA "ï" -- small i,Ü Capital U, dieresis or umlaut mark--> <!ENTITY ntilde CDATA "ñ" -- small n, tilde --> <!ENTITY oacute CDATA "ó" -- small o,Ý Capital Y, acute accent--> <!ENTITY ocirc CDATA "ô" -- small o,Þ Capital THORN, Icelandic ß Small sharp s, German (sz ligature) à Small a, grave accent á Small a, acute accent â Small a, circumflex accent--> <!ENTITY ograve CDATA "ò" -- small o,ã Small a, tilde ä Small a, dieresis or umlaut mark å Small a, ring æ Small ae dipthong (ligature) ç Small c, cedilla è Small e, grave accent--> <!ENTITY oslash CDATA "ø" -- small o, slash --> <!ENTITY otilde CDATA "õ" -- small o, tilde --> <!ENTITY ouml CDATA "ö" -- small o,é Small e, acute accent ê Small e, circumflex accent ë Small e, dieresis or umlaut mark--> <!ENTITY szlig CDATA "ß" -- small sharp s, German(sz ligature)--> <!ENTITY thorn CDATA "þ" -- small thorn, Icelandic --> <!ENTITY uacute CDATA "ú" -- small u,ì Small i, grave accent í Small i, acute accent--> <!ENTITY ucirc CDATA "û" -- small u,î Small i, circumflex accent--> <!ENTITY ugrave CDATA "ù" -- small u, grave accent --> <!ENTITY uuml CDATA "ü" -- small u,ï Small i, dieresis or umlaut mark--> <!ENTITY yacute CDATA "ý" -- small y,ð Small eth, Icelandic ñ Small n, tilde ò Small o, grave accent ó Small o, acute accent--> <!ENTITY yuml CDATA "ÿ" -- small y,ô Small o, circumflex accent õ Small o, tilde ö Small o, dieresis or umlaut mark--> Berners-Lee, Connolly, et. al. Page 72 HTML 2.0 February 8, 1995 5.3 HTML Level 0 DTD This is the Document Type Definition for the HyperText Markup Language as used by minimally conforming World Wide Web applications (HTML Level 0 DTD): <!-- html-0.dtd Document Type Definition for the HyperText Markup Language as used by minimally conforming World Wide Web applications (HTML Level 0 DTD). $Id: html-0.dtd,v 1.11 1995/01/28 05:59:32 connolly Exp $ Author: Daniel W. Connolly <connolly@hal.com> See Also: http://www.hal.com/%7Econnolly/html-spec/index.html http://info.cern.ch/hypertext/WWW/MarkUp2/MarkUp.html --> <!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0 Level 0//EN" -- public identifier for "minimal conformance" version -- -- Typical usage: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Level 0//EN"> <html> ... </html> -- > <!-- Feature Test Entities --> <!ENTITY % HTML.Highlighting "IGNORE"> <!ENTITY % HTML.Forms "IGNORE"> <!ENTITY % head.extra " "> <!ENTITY % linkExtraAttributes " "> <!ENTITY % html PUBLIC "-//IETF//DTD HTML 2.0//EN"> %html; 5.4 HTML Level 1 DTD÷ Division sign ø Small o, slash ù Small u, grave accent ú Small u, acute accent û Small u, circumflex accent ü Small u, dieresis or umlaut mark ý Small y, acute accent þ Small thorn, Icelandic ÿ Small y, dieresis or umlaut mark 14.2. Obsolete Features Thisis the Document Type Definitionsection describes elements that are no longer part of HTML. Client implementors should implement these obsolete elements forthe HyperText Markup Languagecompatibility withLevel 1 Extensions (HTML Level 1 DTD): Berners-Lee, Connolly, et. al. Page 73 HTML 2.0 February 8, 1995 <!-- html-1.dtd Document Type Definition forprevious versions of theHyperText Markup Language with Level 1 Extensions (HTML Level 1 DTD). $Id: html-1.dtd,v 1.6 1994/11/30 23:45:26 connolly Exp $ Author: Daniel W. Connolly <connolly@hal.com> See Also: http://www.hal.com/%7Econnolly/html-spec/index.html http://info.cern.ch/hypertext/WWW/MarkUp2/MarkUp.html --> <!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0 Level 1//EN" -- Typical usage: <!DOCTYPEHTMLPUBLIC "-//IETF//DTDspecification. 14.2.1. Comment Element The Comment element is used to delimit unneeded text and comments. The Comment element has been introduced in some HTMLLevel 1//EN"> <html> ... </html> -- > <!-- Feature Test Entities --> <!ENTITY % HTML.Forms "IGNORE"> <!ENTITY % html PUBLIC "-//IETF//DTDapplications but should be replaced by the SGML comment feature in new HTML2.0//EN"> %html; 7. Glossaryinterpreters (see Section 2.2.5). 14.2.2. Highlighted Phrase Element <HP> TheHTML specification uses these words with precise meanings: attribute A syntactical componentHighlighted Phrase element should be ignored if not implemented. This element has been replaced by more meaningful elements (see Section 8). Example of use: <HP1>first highlighted phrase</HP1>non- highlighted text<HP2>second highlighted phrase</HP2> etc. 14.2.3. Plain Text Element <PLAINTEXT> The Plain Text element is used to terminates the HTML entity and to indicate that what follows is not SGML which does not require parsing. Instead, an old HTTP convention specified that what followed was anHTML element whichASCII (MIME ``text/plain'') body. Its presence isoften used to specify a characteristic quality ofanelement, other than type or content. document type definition (DTD) A DTDoptimization. There isa collectionno closing tag. Example ofdeclarations (entity, element, attribute, link, map, etc.) in SGML syntax that defines the components and structures available for a class (type)use: <PLAINTEXT> 0001 This is line one ofdocuments.a long listing 0002 file from <ANY@HOST.INC.COM> which is sent 14.2.4. Example and Listing Elements <XMP> ... </XMP> and <LISTING> ... </LISTING> The Example and Listing elements have been replaced by the Preformatted Text elementBerners-Lee, Connolly, et. al. Page 74 HTML 2.0 February 8, 1995 A component(Section 10.2). These styles allow text of fixed-width characters to be embedded absolutely as is into thehierarchical structure defined by the document type definition; itdocument. The syntax is: <LISTING> ... </LISTING> or <XMP> ... </XMP> The text between these tags isidentifiedtypically rendered in adocument instancemonospaced font so that any formatting done bydescriptive markup, usually a start-tag and an end-tag. HTML HyperText Markup Language. HTML user agent Any tool used with HTML documents. HTML document A collection of information represented as a sequence of characters. An HTML document consists of data characters and markup. In particular, the markup describes a structure conforming tocharacter spacing on successive lines will be maintained. Between theHTML document type definition. HTTP A generic stateless object-oriented protocol, whichopening and closing tags: * The text maybe usedcontain any ISO Latin-1 printable characters, except formany similar tasks by extendingthecommands, or "methods", used. For example, you might use HTTP for name serversend-tag opener. The Example anddistributed object-oriented systems, With HTTP, the negotiation of data representation allows systemsListing elements have historically used specifications which do not conform tobe built independent ofSGML. Specifically, thedevelopment of new representations. For more information see: http://info.cern.ch/hypertext/WWW/Protocols/HTTP/HTTP2.html (document) instance The document itselftext may contain ISO Latin printable characters, including theactual content with the actual markup. Can be a single document or part of a document instance set that followstag opener, as long it they does not contain theDTD. markup Text added toclosing tag in full. * SGML does not support this form. HTML interpreters may vary on how they interpret other tags within Example and Listing elements. * Line boundaries within thedata of a document to convey information about it. Theretext arefour different kinds of markup: descriptive markup (tags), references, markup declarations, and processing instructions. Multipurpose Internet Mail Extensions (MIME) An extensionrendered as a move toInternet email which providestheBerners-Lee, Connolly, et. al. Page 75 HTML 2.0 February 8, 1995 ability to transfer non-textual data, such as graphics, audio and fax. It is defined in RFC 1341. representation The encodingbeginning ofinformationthe next line, except forinterchange. For example, HTML is a representation of hypertext. rendering Formatting and presenting information. SGML Standard Generalized Markup Language isone immediately following adata encoding that allows the information in documents to be shared - either by other document publishing systemsstart-tag orby applications for electronic delivery, configuration management, database management, inventory control, etc. Defined in ISO 8879:1986 Information Processing Text and Office Systems; Standard Generalized Markup Language (SGML). SGMLS An SGML parser by James Clark, jjc@jclark.com, derived from the ARCSGML parser materials which were written by Charles F. Goldfarb.immediately preceding an end-tag. * Thesource is available at ftp.ifi.uio.no/pub/SGML/SGMLS. tag Descriptive markup. There are two kindshorizontal tab character must be interpreted as the smallest positive nonzero number oftags; start- tags and end-tags. URI Universal Resource Identifiers (URIs) isspaces which will leave thename for a generic WWW identifier. The URI specification simply definesnumber of characters so far on thesyntax for encoding arbitrary naming or addressing schemes, and hasline as alistmultiple ofsuch schemes. See also: http://info.cern.ch/hypertext/WWW/Addressing/Addressing.html WWW A hypertext-based, distributed information system created by researchers at CERN in Switzerland. Users may create, edit or browse hypertext documents. The clients and servers are freely available.See also: http://info.cern.ch/hypertext/WWW/TheProject.html Berners-Lee, Connolly, et. al. Page 76 HTML 2.0 February 8, 1995 7.1 Imperatives may The implementation8. Its use is notobliged to follow this in any way. must If thisrecommended. The Listing element isnot followed, the implementation does not conform to this specification. shall If thisrendered so that at least 132 characters fit on a line. The Example element isnot followed, the implementation does not conformrendered tothis specification. should If thisthat at least 80 characters fit on a line but isnot followed, though the implementation officially conformsotherwise identical to thespecification, undesirable resultsListing element. 14.3. Proposed Features This section describes proposed HTML elements and entities that are not currently supported under HTML Levels 0, 1, or 2@@, but mayoccurbe supported inpractice.the future. 14.3.1. Additional Character Entities To indicate special characters, HTML uses entity or numeric representations. Additional character presentations are proposed: CHARACTER REPRESENTATION Non-breaking space Soft-hyphen ­ Registered ® Copyright © 14.3.2. Defining Instance Element <DFN> ... </DFN> The Defining Instance element indicates the defining instance of a term. The typicalTypicalrendering isdescribed for many elements.bold or bold italic. This element is not widely supported. 14.3.3. Strike Element <STRIKE> ... </STRIKE> The Strike element is proposed to indicate strikethrough, a font style in which a horizontal line appears through characters. This element is nota mandatory part of the specification butwidely supported. 14.3.4. Underline Element <U> ... </U> The Underline element isgiven as guidance for designers andproposed tohelp explain the uses for whichindicate that theelements were intended. 8. References The HTML specification cites these works: HTTP HTTP: A Protocol for Networked Information.text should be rendered as underlined. Thisdocumentproposed tag isavailable at http://info.cern.ch/hypertext/WWW/Protocols/HTTP/HTTP2.h tml. MIME N. Borenstein, N. Freed, MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies, 09/23/1993. (Pages=81) (Format=.txt, .ps) (Obsoletes RFC1341) (Updatednot supported byRFC1590). Berners-Lee, Connolly, et. al. Page 77all HTML2.0 February 8, 1995 SGML ISO Standard 8879:1986 Information Processing Text and Office Systems; Standard Generalized Markup Language (SGML). SGMLS An SGML parser by James Clark, jjc@jclark.com, derived from the ARCSGML parser materials which were written by Charles F. Goldfarb.interpreters. Example of use: Thesourcetext <U>shown here</U> isavailable at ftp.ifi.uio.no/pub/SGML/SGMLS. URI Universal Resource Identifiers. Available by anonymous FTPrendered in the document asPostscript (info.cern.ch/pub/www/doc/url.ps) or text (info.cern.ch/pub/www/doc/url.txt) WWW The World Wide Web , a global information initiative. For bootstrap information, telnet info.cern.ch or find documents by ftp://info.cern.ch/pub/www/doc. 9.underlined. 15. Acknowledgments The HTML document type was designed by Tim Berners-Lee at CERN as part of the 1990 World Wide Web project. In 1992, Dan Connolly wrote the HTML Document Type Definition (DTD) and a brief HTML specification. Since 1993, a wide variety of Internet participants have contributed to the evolution of HTML, which has included the addition of in-line images introduced by the NCSA Mosaic software for WWW. Dave Raggett played an important role in deriving the FORMS material from the HTML+ specification. Dan Connolly and Karen Olson Muldrow rewrote the HTML Specification in 1994. The document was then edited by the HTML working group as a whole, with updates being made by Eric Schieler, Mike Knezovich, and Eric W. Sink at Spyglass, Inc. Finally, Roy Fielding restructured the entire draft into its current form. Special thanks to the many people who have contributed to this specification:-TerryAllen; O'Reilly & Associates; terry@ora.com -Allen MarcAndreessen; Netscape Communications Corp; marca@mcom.com Berners-Lee, Connolly, et. al. Page 78 HTML 2.0 February 8, 1995 -Andreessen Tim Berners-Lee PaulBurchard; The Geometry Center, University of Minnesota; burchard@geom.umn.edu -Burchard JamesClark; jjc@jclark.com -Clark Daniel W.Connolly; HaL Computer Systems; connolly@hal.com -Connolly RoyFielding; University of California, Irvine; fielding@ics.uci.edu -T. Fielding PeterFlynn; University College Cork, Ireland; pflynn@www.ucc.ie -Flynn JayGlicksman; Enterprise Integration Technology; jay@eit.com -Glicksman PaulGrosso; ArborText, Inc.; paul@arbortext.com -Grosso EduardoGutentag; Sun Microsystems; eduardo@Eng.Sun.com -Gutentag BillHefley; Software Engineering Institute, Carnegie Mellon University; weh@sei.cmu.edu -Hefley Chung-JenHo; Xerox Corporation; cho@xsoft.xerox.com -Ho MikeKnezovich; Spyglass, Inc.; mike@spyglass.com - Tim Berners-Lee; CERN; timbl@info.cern.ch -Knezovich TomMagliery; NCSA; mag@ncsa.uiuc.edu -Magliery MurrayMaloney; Toronto Development Centre, The Santa Cruz Operation (SCO); murray@sco.com -Maloney LarryMasinter; Xerox Palo Alto Research Center; masinter@parc.xerox.com -Masinter Karen OlsonMuldrow; HaL Computer Systems; karen@hal.com -Muldrow BillPerry, Spry, Inc., wmperry@spry.com -Perry DaveRaggett, Hewlett Packard, dsr@hplb.hpl.hp.com -Raggett E. CorprewReed; Cold Spring Harbor Laboratory; corp@cshl.org -Reed YuriRubinsky; SoftQuad, Inc.; yuri@sq.com -Rubinsky EricSchieler; Spyglass, Inc.; eschieler@spyglass.com -Schieler James L.Seidman; Spyglass, Inc.; jim@spyglass.com -Seidman Eric W.Sink; Spyglass, Inc.; eric@spyglass.com Berners-Lee, Connolly, et. al. Page 79 HTML 2.0 February 8, 1995 -Sink StuartWeibel; OCLC Office of Research; weibel@oclc.org -Weibel ChrisWilson; Spry, Inc.; cwilson@spry.com 10. Author'sWilson Francois Yergeau 15.1. Authors' Addresses Tim Berners-Leetimbl@quag.lcs.mit.eduDirector, W3 Consortium MIT Laboratory for Computer Science 545 Technology Square Cambridge, MA 02139, U.S.A. Tel: +1 (617) 253 9670 Fax: +1 (617) 258 8682 Email: timbl@w3.org Daniel W. ConnollyHal Software Systems 3006A Longhorn Blvd. Austin, TX 78758 phone: (512) 834-9962 extension 5010 fax: (512) 823-9963 URL: http://www.hal.com/~connolly email: connolly@hal.com Berners-Lee, Connolly, et. al. Page 80Research Technical Staff, W3 Consortium MIT Laboratory for Computer Science 545 Technology Square Cambridge, MA 02139, U.S.A. Fax: +1 (617) 258 8682 Email: connolly@w3.org URI: http://www.w3.org/hypertext/WWW/People/Connolly/ ----