HTML 4 Reference Manual

Abstract

This specification defines the HyperText Markup Language (HTML), thepublishing language of the World Wide Web. This specification defines HTML4.01, which is a subversion of HTML 4. In addition to the text, multimedia, andhyperlink features of the previous versions of HTML (HTML 3.2 [HTML32] and HTML 2.0 [RFC1866]), HTML 4supports more multimedia options, scripting languages, style sheets, betterprinting facilities, and documents that are more accessible to users withdisabilities. HTML 4 also takes great strides towards the internationalizationof documents, with the goal of making the Web truly World Wide.

HTML 4 is an SGML application conforming to International Standard ISO 8879-- Standard Generalized Markup Language [ISO8879].

Status of this document

This section describes the status of this document at the time of itspublication. Other documents may supersede this document. The latest status ofthis document series is maintained at the W3C.

This document specifies HTML 4.01, which is part of the HTML 4 line ofspecifications. The first version of HTML 4 was HTML 4.0 [HTML40], publishedon 18 December 1997 and revised 24 April 1998. This specification is the firstHTML 4.01 Recommendation. It includes non-editorial changes since the 24 April version of HTML4.0. There have been some changes to the DTDs, for example. This documentobsoletes previous versions of HTML 4.0, although W3C will continue to makethose specifications and their DTDs available at the W3C Web site.

This document has been reviewed by W3C Members and other interested partiesand has been endorsed by the Director as a W3C Recommendation. It is a stabledocument and may be used as reference material or cited as a normativereference from another document. W3C's role in making the Recommendation is todraw attention to the specification and to promote its widespread deployment.This enhances the functionality and interoperability of the Web.

W3C recommends that user agents and authors (and in particular, authoringtools) produce HTML 4.01 documents rather than HTML 4.0 documents. W3Crecommends that authors produce HTML 4 documents instead of HTML 3.2 documents.For reasons of backward compatibility, W3C also recommends that toolsinterpreting HTML 4 continue to support HTML 3.2 and HTML 2.0 as well.

For information about the next generation of HTML, "The Extensible HyperTextMarkup Language" [XHTML], please refer to the W3C HTML Activity and the list of W3C Technical Reports.

This document has been produced as part of the W3C HTML Activity. The goals of the HTML Working Group (Members only) are discussed in the HTML Working Groupcharter (Membersonly).

A list of current W3C Recommendations and other technical documents can befound at http://www.w3.org/TR.

Public discussion on HTML features takes place on www-html@w3.org (archives ofwww-html@w3.org).

Available languages

The English version of this specification is the only normative version.However, for translations of this document, see http://www.w3.org/MarkUp/html4-updates/translations.

Errata

The list of known errors in this specification is available at:

http://www.w3.org/MarkUp/html4-updates/errata

Please report errors in this document to www-html-editor@w3.org.

Full Daftar Isi

1. About the HTML 4Specification
   1. How the specification isorganized
   2. Document conventions
      1. Elements andattributes
      2. Notes and examples
   3. Acknowledgments
      1. Acknowledgments for thecurrent revision
   4. Copyright Notice
2. Introduction toHTML 4
   1. What is the World WideWeb?
      1. Introduction toURIs
      2. Fragmentidentifiers
      3. Relative URIs
   2. What is HTML?
      1. A brief history ofHTML
   3. HTML 4
      1. Internationalization
      2. Accessibility
      3. Tables
      4. Compounddocuments
      5. Style sheets
      6. Scripting
      7. Printing
   4. Authoring documents withHTML 4
      1. Separate structure andpresentation
      2. Consider universalaccessibility to the Web
      3. Help user agents withincremental rendering
3. On SGML andHTML
   1. Introduction toSGML
   2. SGML constructs used inHTML
      1. Elements
      2. Attributes
      3. Characterreferences
      4. Comments
   3. How to read the HTMLDTD
      1. DTD Comments
      2. Parameter entitydefinitions
      3. Elementdeclarations
         • Content modeldefinitions
      4. Attributedeclarations
         • DTD entities inattribute definitions
         • Booleanattributes
4. Conformance:requirements and recommendations
   1. Definitions
   2. SGML
   3. The text/html content type
5. HTML DocumentRepresentation - Character sets, character encodings, and entities
   1. The Document CharacterSet
   2. Character encodings
      1. Choosing an encoding
         • Notes on specificencodings
      2. Specifying the characterencoding
   3. Character references
      1. Numeric characterreferences
      2. Character entityreferences
   4. Undisplayablecharacters
6. Basic HTML datatypes - Character data, colors, lengths, URIs, content types, etc.
   1. Case information
   2. SGML basic types
   3. Text strings
   4. URIs
   5. Colors
      1. Notes on using colors
   6. Lengths
   7. Content types (MIMEtypes)
   8. Language codes
   9. Character encodings
   10. Single characters
   11. Dates and times
   12. Link types
   13. Media descriptors
   14. Script data
   15. Style sheet data
   16. Frame target names
7. The globalstructure of an HTML document - The HEAD and BODY of a document
   1. Introduction to thestructure of an HTML document
   2. HTML versioninformation
   3. The HTML element
   4. The document head
      1. The HEAD element
      2. The TITLE element
      3. The titleattribute
      4. Meta data
         • Specifying metadata
         • The META element
         • Meta dataprofiles
   5. The document body
      1. The BODY element
      2. Element identifiers:the id and class attributes
      3. Block-level and inlineelements
      4. Grouping elements: theDIV and SPANelements
      5. Headings: The H1, H2, H3, H4, H5,H6 elements
      6. The ADDRESS element
8. Languageinformation and text direction - International considerations fortext
   1. Specifying the languageof content: the lang attribute
      1. Language codes
      2. Inheritance oflanguage codes
      3. Interpretation oflanguage codes
   2. Specifying thedirection of text and tables: the dir attribute
      1. Introduction to thebidirectional algorithm
      2. Inheritance of textdirection information
      3. Setting the directionof embedded text
      4. Overriding thebidirectional algorithm: the BDO element
      5. Character referencesfor directionality and joining control
      6. The effect of stylesheets on bidirectionality
9. Text -Paragraphs, Lines, and Phrases
   1. White space
   2. Structured text
      1. Phrase elements: EM, STRONG, DFN, CODE, SAMP, KBD, VAR,CITE, ABBR, and ACRONYM
      2. Quotations: The BLOCKQUOTE and Q elements
         • Renderingquotations
      3. Subscripts andsuperscripts: the SUB and SUP elements
   3. Lines and Paragraphs
      1. Paragraphs: the P element
      2. Controlling linebreaks
         • Forcing a line break:the BR element
         • Prohibiting a linebreak
      3. Hyphenation
      4. Preformatted text: ThePRE element
      5. Visual rendering ofparagraphs
   4. Marking document changes:The INS and DEL elements
10. Lists -Unordered, Ordered, and Definition Lists
    1. Introduction tolists
    2. Unordered lists (UL), orderedlists (OL), and list items (LI)
    3. Definition lists: the DL, DT, and DD elements
       1. Visual rendering oflists
    4. The DIR and MENU elements
11. Tables
    1. Introduction totables
    2. Elements forconstructing tables
       1. The TABLE element
          • Tabledirectionality
       2. Table Captions: TheCAPTION element
       3. Row groups: the THEAD, TFOOT, and TBODY elements
       4. Column groups: theCOLGROUP and COLelements
          • The COLGROUP element
          • The COL element
          • Calculating thenumber of columns in a table
          • Calculating thewidth of columns
       5. Table rows: The TR element
       6. Table cells: TheTH and TD elements
          • Cells that spanseveral rows or columns
    3. Table formatting byvisual user agents
       1. Borders andrules
       2. Horizontal andvertical alignment
          • Inheritance ofalignment specifications
       3. Cell margins
    4. Table rendering bynon-visual user agents
       1. Associating headerinformation with data cells
       2. Categorizingcells
       3. Algorithm to findheading information
    5. Sample table
12. Links -Hypertext and Media-Independent Links
    1. Introduction to linksand anchors
       1. Visiting a linkedresource
       2. Other linkrelationships
       3. Specifying anchors andlinks
       4. Link titles
       5. Internationalizationand links
    2. The A element
       1. Syntax of anchornames
       2. Nested links areillegal
       3. Anchors with theid attribute
       4. Unavailable andunidentifiable resources
    3. Document relationships:the LINK element
       1. Forward and reverselinks
       2. Links and externalstyle sheets
       3. Links and searchengines
    4. Path information: theBASE element
       1. Resolving relative URIs
13. Objects,Images, and Applets
    1. Introduction toobjects, images, and applets
    2. Including an image:the IMG element
    3. Generic inclusion: theOBJECT element
       1. Rules for renderingobjects
       2. Objectinitialization: the PARAM element
       3. Global namingschemes for objects
       4. Object declarationsand instantiations
    4. Including an applet:the APPLET element
    5. Notes on embeddeddocuments
    6. Image maps
       1. Client-side imagemaps: the MAP and AREAelements
          • Client-side imagemap examples
       2. Server-side imagemaps
    7. Visual presentation ofimages, objects, and applets
       1. Width andheight
       2. White space aroundimages and objects
       3. Borders
       4. Alignment
    8. How to specifyalternate text
14. StyleSheets - Adding style to HTML documents
    1. Introduction to stylesheets
    2. Adding style toHTML
       1. Setting the defaultstyle sheet language
       2. Inline styleinformation
       3. Header styleinformation: the STYLE element
       4. Media types
    3. External stylesheets
       1. Preferred andalternate style sheets
       2. Specifying externalstyle sheets
    4. Cascading stylesheets
       1. Media-dependentcascades
       2. Inheritance andcascading
    5. Hiding style data fromuser agents
    6. Linking to stylesheets with HTTP headers
15. Alignment,font styles, and horizontal rules
    1. Formatting
       1. Backgroundcolor
       2. Alignment
       3. Floatingobjects
          • Float anobject
          • Float textaround an object
    2. Fonts
       1. Font styleelements: the TT, I,B, BIG, SMALL, STRIKE, S, and U elements
       2. Font modifierelements: FONT and BASEFONT
    3. Rules: the HR element
16. Frames - Multi-view presentation of documents
    1. Introduction toframes
    2. Layout of frames
       1. The FRAMESET element
          • Rows andcolumns
          • Nested framesets
          • Sharing data amongframes
       2. The FRAME element
          • Setting theinitial contents of a frame
          • Visual renderingof a frame
    3. Specifying targetframe information
       1. Setting the defaulttarget for links
       2. Targetsemantics
    4. Alternate content
       1. The NOFRAMES element
       2. Long descriptions offrames
    5. Inline frames: theIFRAME element
17. Forms -User-input Forms: Text Fields, Buttons, Menus, and more
    1. Introduction toforms
    2. Controls
       1. Controltypes
    3. The FORM element
    4. The INPUT element
       1. Control typescreated with INPUT
       2. Examples of formscontaining INPUT controls
    5. The BUTTON element
    6. The SELECT, OPTGROUP, and OPTION elements
       1. Pre-selectedoptions
    7. The TEXTAREA element
    8. The ISINDEX element
    9. Labels
       1. The LABEL element
    10. Adding structure toforms: the FIELDSET and LEGEND elements
    11. Giving focus to anelement
        1. Tabbingnavigation
        2. Access keys
    12. Disabled andread-only controls
        1. Disabledcontrols
        2. Read-onlycontrols
    13. Form submission
        1. Form submissionmethod
        2. Successfulcontrols
        3. Processing formdata
           • Step one:Identify the successful controls
           • Step two: Build aform data set
           • Step three:Encode the form data set
           • Step four: Submitthe encoded form data set
        4. Form contenttypes
           • application/x-www-form-urlencoded
           • multipart/form-data
18. Scripts- Animated Documents and Smart Forms
    1. Introduction toscripts
    2. Designing documentsfor user agents that support scripting
       1. The SCRIPT element
       2. Specifying thescripting language
          • The defaultscripting language
          • Localdeclaration of a scripting language
          • References toHTML elements from a script
       3. Intrinsicevents
       4. Dynamicmodification of documents
    3. Designing documentsfor user agents that don't support scripting
       1. The NOSCRIPT element
       2. Hiding script datafrom user agents
19. SGML referenceinformation for HTML - Formal definition of HTML and validation
    1. DocumentValidation
    2. Sample SGMLcatalog
20. SGML Declaration of HTML4
    1. SGMLDeclaration
21. Document Type Definition
22. Transitional Document Type Definition
23. Frameset Document Type Definition
24. Character entityreferences in HTML 4
    1. Introduction tocharacter entity references
    2. Character entityreferences for ISO 8859-1 characters
       1. The list ofcharacters
    3. Character entityreferences for symbols, mathematical symbols, and Greek letters
       1. The list ofcharacters
    4. Character entityreferences for markup-significant and internationalization characters
       1. The list ofcharacters

1. Changes
   1. Changes between 24April 1998 HTML 4.0 and 24 December 1999 HTML 4.01 versions
      1. Changes to thespecification
         • Generalchanges
         • On SGML andHTML
         • HTML DocumentRepresentation
         • Basic HTML datatypes
         • Global structureof an HTML document
         • Languageinformation and text direction
         • Tables
         • Links
         • Objects, Images,and Applets
         • Style Sheets inHTML Documents
         • Frames
         • Forms
         • SGMLDeclaration
         • StrictDTD
         • Notes
         • References
      2. Errors that werecorrected
      3. Minor typographicalerrors that were corrected
      4. Clarifications
      5. Known Browserproblems
   2. Changes between 18December 1997 and 24 April 1998 versions
      1. Errors that werecorrected
      2. Minor typographicalerrors that were corrected
   3. Changes between HTML3.2 and HTML 4.0 (18 December 1997)
      1. Changes toelements
         • Newelements
         • Deprecatedelements
         • Obsoleteelements
      2. Changes toattributes
      3. Changes foraccessibility
      4. Changes for metadata
      5. Changes fortext
      6. Changes forlinks
      7. Changes fortables
      8. Changes for images,objects, and image maps
      9. Changes forforms
      10. Changes for stylesheets
      11. Changes forframes
      12. Changes forscripting
      13. Changes forinternationalization
2. Performance,Implementation, and Design Notes
   1. Notes on invaliddocuments
   2. Special characters inURI attribute values
      1. Non-ASCII charactersin URI attribute values
      2. Ampersands in URIattribute values
   3. SGML implementationnotes
      1. Line breaks
      2. Specifying non-HTMLdata
         • Elementcontent
         • Attributevalues
      3. SGML features withlimited support
      4. Booleanattributes
      5. MarkedSections
      6. ProcessingInstructions
      7. Shorthandmarkup
   4. Notes on helping searchengines index your Web site
      1. Search robots
         • The robots.txtfile
         • Robots and the METAelement
   5. Notes on tables
      1. Design rationale
         • Dynamicreformatting
         • Incrementaldisplay
         • Structure andpresentation
         • Row and columngroups
         • Accessibility
      2. Recommended LayoutAlgorithms
         • Fixed LayoutAlgorithm
         • AutolayoutAlgorithm
   6. Notes on forms
      1. Incrementaldisplay
      2. Futureprojects
   7. Notes on scripting
      1. Reserved syntax forfuture script macros
         • Current Practicefor Script Macros
   8. Notes onframes
   9. Notes onaccessibility
   10. Notes on security
       1. Security issues forforms

• References
  1. Normativereferences
  2. Informativereferences
• Index ofElements
• Index ofAttributes
• Index