Abstract

This document is a strict subset of the full HTML5 specification that omits user-agent (UA) implementation details. It is targeted toward Web authors and others who are not UA implementors and who want a view of the HTML specification that focuses more precisely on details relevant to using the HTML language to create Web documents and Web applications. Because this document does not provide implementation conformance criteria, UA implementors should not rely on it, but should instead refer to the full HTML5 specification.

This document is an automated redaction of the full HTML5 specification. As such, the two documents are supposed to agree on normative matters concerning Web authors. However, if the documents disagree, this is a bug in the redaction process and the unredacted full HTML specification takes precedence. Readers are encouraged to report such discrepancies as bugs in the bug tracking system of the HTML Working Group.

Status of This document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

If you wish to make comments regarding this document in a manner that is tracked by the W3C, please submit them via using our public bug database. If you cannot do this then you can also e-mail feedback to public-html-comments@w3.org (subscribe, archives), and arrangements will be made to transpose the comments to our public bug database. All feedback is welcome.

The bulk of the text of this specification is also available in the WHATWG Web Applications 1.0 specification, under a license that permits reuse of the specification text.

The working groups maintains a list of all bug reports that the editors have not yet tried to address and a list of issues for which the chairs have not yet declared a decision. These bugs and issues apply to multiple HTML-related specifications, not just this one.

Implementors should be aware that this specification is not stable. Implementors who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways. Vendors interested in implementing this specification before it eventually reaches the Candidate Recommendation stage should join the aforementioned mailing lists and take part in the discussions.

This is a work in progress! For the latest updates from the HTML WG, possibly including important bug fixes, please look at the editor's draft instead.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

The latest stable version of the editor's draft of this specification is always available on the W3C CVS server. There are various ways to follow the change history for this specification:

Browsable version-control record of all changes:
Github repository (real-time updates): https://github.com/w3c/html/commits/master
CVSWeb interface (hourly updates): http://dev.w3.org/cvsweb/html5/spec/
E-mail notifications of changes:
HTML-Commits mailing list (commit notifications for dev.w3.org/html5): http://lists.w3.org/Archives/Public/public-html-commits/latest

The W3C HTML Working Group is the W3C working group responsible for this specification's progress along the W3C Recommendation track. This specification is the 25 October 2012 Working Draft.

Work on this specification is also done at the WHATWG. The W3C HTML working group actively pursues convergence with the WHATWG, as required by the W3C HTML working group charter. There are various ways to follow this work at the WHATWG:

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

Table of Contents

  1. 1 Introduction
    1. 1.1 Background
    2. 1.2 Audience
    3. 1.3 Scope
    4. 1.4 History
    5. 1.5 Design notes
      1. 1.5.1 Serializability of script execution
      2. 1.5.2 Compliance with other specifications
    6. 1.6 HTML vs XHTML
    7. 1.7 Structure of this specification
      1. 1.7.1 How to read this specification
      2. 1.7.2 Typographic conventions
    8. 1.8 Privacy concerns
    9. 1.9 A quick introduction to HTML
      1. 1.9.1 Writing secure applications with HTML
      2. 1.9.2 Common pitfalls to avoid when using the scripting APIs
    10. 1.10 Conformance requirements for authors
      1. 1.10.1 Presentational markup
      2. 1.10.2 Syntax errors
      3. 1.10.3 Restrictions on content models and on attribute values
    11. 1.11 Recommended reading
  2. 2 Common infrastructure
    1. 2.1 Terminology
      1. 2.1.1 Resources
      2. 2.1.2 XML
      3. 2.1.3 DOM trees
      4. 2.1.4 Scripting
      5. 2.1.5 Plugins
      6. 2.1.6 Character encodings
    2. 2.2 Conformance requirements
      1. 2.2.1 Extensibility
    3. 2.3 Case-sensitivity and string comparison
    4. 2.4 Common microsyntaxes
      1. 2.4.1 Boolean attributes
      2. 2.4.2 Keywords and enumerated attributes
      3. 2.4.3 Numbers
        1. 2.4.3.1 Signed integers
        2. 2.4.3.2 Non-negative integers
        3. 2.4.3.3 Floating-point numbers
        4. 2.4.3.4 Lists of integers
      4. 2.4.4 Dates and times
        1. 2.4.4.1 Months
        2. 2.4.4.2 Dates
        3. 2.4.4.3 Yearless dates
        4. 2.4.4.4 Times
        5. 2.4.4.5 Local dates and times
        6. 2.4.4.6 Time zones
        7. 2.4.4.7 Global dates and times
        8. 2.4.4.8 Weeks
        9. 2.4.4.9 Durations
        10. 2.4.4.10 Vaguer moments in time
      5. 2.4.5 Colors
      6. 2.4.6 Space-separated tokens
      7. 2.4.7 Comma-separated tokens
      8. 2.4.8 References
      9. 2.4.9 Media queries
    5. 2.5 URLs
      1. 2.5.1 Terminology
      2. 2.5.2 Base URLs
      3. 2.5.3 Resolving URLs
      4. 2.5.4 Interfaces for URL manipulation
      5. 2.5.5 CORS settings attributes
    6. 2.6 Common DOM interfaces
      1. 2.6.1 Reflecting content attributes in IDL attributes
      2. 2.6.2 Collections
        1. 2.6.2.1 HTMLAllCollection
        2. 2.6.2.2 HTMLFormControlsCollection
        3. 2.6.2.3 HTMLOptionsCollection
      3. 2.6.3 DOMStringMap
      4. 2.6.4 Transferable objects
      5. 2.6.5 DOM feature strings
    7. 2.7 Namespaces
  3. 3 Semantics, structure, and APIs of HTML documents
    1. 3.1 Documents
      1. 3.1.1 The Document object
      2. 3.1.2 Security
      3. 3.1.3 Resource metadata management
      4. 3.1.4 DOM tree accessors
    2. 3.2 Elements
      1. 3.2.1 Semantics
      2. 3.2.2 Elements in the DOM
      3. 3.2.3 Global attributes
        1. 3.2.3.1 The id attribute
        2. 3.2.3.2 The title attribute
        3. 3.2.3.3 The lang and xml:lang attributes
        4. 3.2.3.4 The translate attribute
        5. 3.2.3.5 The xml:base attribute (XML only)
        6. 3.2.3.6 The dir attribute
        7. 3.2.3.7 The class attribute
        8. 3.2.3.8 The style attribute
        9. 3.2.3.9 Embedding custom non-visible data with the data-* attributes
      4. 3.2.4 Element definitions
        1. 3.2.4.1 Attributes
      5. 3.2.5 Content models
        1. 3.2.5.1 Kinds of content
          1. 3.2.5.1.1 Metadata content
          2. 3.2.5.1.2 Flow content
          3. 3.2.5.1.3 Sectioning content
          4. 3.2.5.1.4 Heading content
          5. 3.2.5.1.5 Phrasing content
          6. 3.2.5.1.6 Embedded content
          7. 3.2.5.1.7 Interactive content
          8. 3.2.5.1.8 Palpable content
        2. 3.2.5.2 Transparent content models
        3. 3.2.5.3 Paragraphs
      6. 3.2.6 Requirements relating to bidirectional-algorithm formatting characters
      7. 3.2.7 WAI-ARIA
        1. 3.2.7.1 ARIA Role Attribute
        2. 3.2.7.2 State and Property Attributes
        3. 3.2.7.3 Strong Native Semantics
        4. 3.2.7.4 Implicit ARIA Semantics
    3. 3.3 Dynamic markup insertion
      1. 3.3.1 Opening the input stream
      2. 3.3.2 Closing the input stream
      3. 3.3.3 document.write()
      4. 3.3.4 document.writeln()
  4. 4 The elements of HTML
    1. 4.1 The root element
      1. 4.1.1 The html element
    2. 4.2 Document metadata
      1. 4.2.1 The head element
      2. 4.2.2 The title element
      3. 4.2.3 The base element
      4. 4.2.4 The link element
      5. 4.2.5 The meta element
        1. 4.2.5.1 Standard metadata names
        2. 4.2.5.2 Other metadata names
        3. 4.2.5.3 Pragma directives
        4. 4.2.5.4 Other pragma directives
        5. 4.2.5.5 Specifying the document's character encoding
      6. 4.2.6 The style element
      7. 4.2.7 Styling
    3. 4.3 Scripting
      1. 4.3.1 The script element
        1. 4.3.1.1 Scripting languages
        2. 4.3.1.2 Restrictions for contents of script elements
        3. 4.3.1.3 Inline documentation for external scripts
      2. 4.3.2 The noscript element
    4. 4.4 Sections
      1. 4.4.1 The body element
      2. 4.4.2 The section element
      3. 4.4.3 The nav element
      4. 4.4.4 The article element
      5. 4.4.5 The aside element
      6. 4.4.6 The h1, h2, h3, h4, h5, and h6 elements
      7. 4.4.7 The hgroup element
      8. 4.4.8 The header element
      9. 4.4.9 The footer element
      10. 4.4.10 The address element
      11. 4.4.11 Headings and sections
        1. 4.4.11.1 Creating an outline
    5. 4.5 Grouping content
      1. 4.5.1 The p element
      2. 4.5.2 The hr element
      3. 4.5.3 The pre element
      4. 4.5.4 The blockquote element
      5. 4.5.5 The ol element
      6. 4.5.6 The ul element
      7. 4.5.7 The li element
      8. 4.5.8 The dl element
      9. 4.5.9 The dt element
      10. 4.5.10 The dd element
      11. 4.5.11 The figure element
      12. 4.5.12 The figcaption element
      13. 4.5.13 The div element
    6. 4.6 Text-level semantics
      1. 4.6.1 The a element
      2. 4.6.2 The em element
      3. 4.6.3 The strong element
      4. 4.6.4 The small element
      5. 4.6.5 The s element
      6. 4.6.6 The cite element
      7. 4.6.7 The q element
      8. 4.6.8 The dfn element
      9. 4.6.9 The abbr element
      10. 4.6.10 The time element
      11. 4.6.11 The code element
      12. 4.6.12 The var element
      13. 4.6.13 The samp element
      14. 4.6.14 The kbd element
      15. 4.6.15 The sub and sup elements
      16. 4.6.16 The i element
      17. 4.6.17 The b element
      18. 4.6.18 The u element
      19. 4.6.19 The mark element
      20. 4.6.20 The ruby element
      21. 4.6.21 The rt element
      22. 4.6.22 The rp element
      23. 4.6.23 The bdi element
      24. 4.6.24 The bdo element
      25. 4.6.25 The span element
      26. 4.6.26 The br element
      27. 4.6.27 The wbr element
      28. 4.6.28 Usage summary
    7. 4.7 Edits
      1. 4.7.1 The ins element
      2. 4.7.2 The del element
      3. 4.7.3 Attributes common to ins and del elements
      4. 4.7.4 Edits and paragraphs
      5. 4.7.5 Edits and lists
      6. 4.7.6 Edits and tables
    8. 4.8 Embedded content
      1. 4.8.1 The img element
        1. 4.8.1.1 Requirements for providing text to act as an alternative for images
          1. 4.8.1.1.1 General guidelines
          2. 4.8.1.1.2 A link or button containing nothing but the image
          3. 4.8.1.1.3 A phrase or paragraph with an alternative graphical representation: charts, diagrams, graphs, maps, illustrations
          4. 4.8.1.1.4 A short phrase or label with an alternative graphical representation: icons, logos
          5. 4.8.1.1.5 Text that has been rendered to a graphic for typographical effect
          6. 4.8.1.1.6 A graphical representation of some of the surrounding text
          7. 4.8.1.1.7 A purely decorative image that doesn't add any information
          8. 4.8.1.1.8 A group of images that form a single larger picture with no links
          9. 4.8.1.1.9 A group of images that form a single larger picture with links
          10. 4.8.1.1.10 A key part of the content
          11. 4.8.1.1.11 An image not intended for the user
      2. 4.8.2 The iframe element
      3. 4.8.3 The embed element
      4. 4.8.4 The object element
      5. 4.8.5 The param element
      6. 4.8.6 The video element
      7. 4.8.7 The audio element
      8. 4.8.8 The source element
      9. 4.8.9 The track element
      10. 4.8.10 Media elements
        1. 4.8.10.1 Error codes
        2. 4.8.10.2 Location of the media resource
        3. 4.8.10.3 MIME types
        4. 4.8.10.4 Network states
        5. 4.8.10.5 Loading the media resource
        6. 4.8.10.6 Offsets into the media resource
        7. 4.8.10.7 Ready states
        8. 4.8.10.8 Playing the media resource
        9. 4.8.10.9 Seeking
        10. 4.8.10.10 Media resources with multiple media tracks
          1. 4.8.10.10.1 AudioTrackList and VideoTrackList objects
          2. 4.8.10.10.2 Selecting specific audio and video tracks declaratively
        11. 4.8.10.11 Synchronising multiple media elements
          1. 4.8.10.11.1 Introduction
          2. 4.8.10.11.2 Media controllers
          3. 4.8.10.11.3 Assigning a media controller declaratively
        12. 4.8.10.12 Timed text tracks
          1. 4.8.10.12.1 Text track model
          2. 4.8.10.12.2 Sourcing in-band text tracks
          3. 4.8.10.12.3 Text track API
          4. 4.8.10.12.4 Text tracks describing chapters
        13. 4.8.10.13 User interface
        14. 4.8.10.14 Time ranges
        15. 4.8.10.15 Event definitions
        16. 4.8.10.16 Event summary
        17. 4.8.10.17 Best practices for authors using media elements
      11. 4.8.11 The canvas element
      12. 4.8.12 The map element
      13. 4.8.13 The area element
      14. 4.8.14 Image maps
      15. 4.8.15 MathML
      16. 4.8.16 SVG
      17. 4.8.17 Dimension attributes
    9. 4.9 Tabular data
      1. 4.9.1 The table element
        1. 4.9.1.1 Techniques for describing tables
        2. 4.9.1.2 Techniques for table layout
      2. 4.9.2 The caption element
      3. 4.9.3 The colgroup element
      4. 4.9.4 The col element
      5. 4.9.5 The tbody element
      6. 4.9.6 The thead element
      7. 4.9.7 The tfoot element
      8. 4.9.8 The tr element
      9. 4.9.9 The td element
      10. 4.9.10 The th element
      11. 4.9.11 Attributes common to td and th elements
      12. 4.9.12 Examples
    10. 4.10 Forms
      1. 4.10.1 Introduction
        1. 4.10.1.1 Writing a form's user interface
        2. 4.10.1.2 Implementing the server-side processing for a form
        3. 4.10.1.3 Configuring a form to communicate with a server
        4. 4.10.1.4 Client-side form validation
        5. 4.10.1.5 Date, time, and number formats
      2. 4.10.2 Categories
      3. 4.10.3 The form element
      4. 4.10.4 The fieldset element
      5. 4.10.5 The legend element
      6. 4.10.6 The label element
      7. 4.10.7 The input element
        1. 4.10.7.1 States of the type attribute
          1. 4.10.7.1.1 Hidden state (type=hidden)
          2. 4.10.7.1.2 Text (type=text) state and Search state (type=search)
          3. 4.10.7.1.3 Telephone state (type=tel)
          4. 4.10.7.1.4 URL state (type=url)
          5. 4.10.7.1.5 E-mail state (type=email)
          6. 4.10.7.1.6 Password state (type=password)
          7. 4.10.7.1.7 Date and Time state (type=datetime)
          8. 4.10.7.1.8 Date state (type=date)
          9. 4.10.7.1.9 Month state (type=month)
          10. 4.10.7.1.10 Week state (type=week)
          11. 4.10.7.1.11 Time state (type=time)
          12. 4.10.7.1.12 Local Date and Time state (type=datetime-local)
          13. 4.10.7.1.13 Number state (type=number)
          14. 4.10.7.1.14 Range state (type=range)
          15. 4.10.7.1.15 Color state (type=color)
          16. 4.10.7.1.16 Checkbox state (type=checkbox)
          17. 4.10.7.1.17 Radio Button state (type=radio)
          18. 4.10.7.1.18 File Upload state (type=file)
          19. 4.10.7.1.19 Submit Button state (type=submit)
          20. 4.10.7.1.20 Image Button state (type=image)
          21. 4.10.7.1.21 Reset Button state (type=reset)
          22. 4.10.7.1.22 Button state (type=button)
        2. 4.10.7.2 Common input element attributes
          1. 4.10.7.2.1 The autocomplete attribute
          2. 4.10.7.2.2 The dirname attribute
          3. 4.10.7.2.3 The list attribute
          4. 4.10.7.2.4 The readonly attribute
          5. 4.10.7.2.5 The size attribute
          6. 4.10.7.2.6 The required attribute
          7. 4.10.7.2.7 The multiple attribute
          8. 4.10.7.2.8 The maxlength attribute
          9. 4.10.7.2.9 The pattern attribute
          10. 4.10.7.2.10 The min and max attributes
          11. 4.10.7.2.11 The step attribute
          12. 4.10.7.2.12 The placeholder attribute
        3. 4.10.7.3 Common input element APIs
      8. 4.10.8 The button element
      9. 4.10.9 The select element
      10. 4.10.10 The datalist element
      11. 4.10.11 The optgroup element
      12. 4.10.12 The option element
      13. 4.10.13 The textarea element
      14. 4.10.14 The keygen element
      15. 4.10.15 The output element
      16. 4.10.16 The progress element
      17. 4.10.17 The meter element
      18. 4.10.18 Association of controls and forms
      19. 4.10.19 Attributes common to form controls
        1. 4.10.19.1 Naming form controls
        2. 4.10.19.2 Enabling and disabling form controls
        3. 4.10.19.3 Autofocusing a form control
        4. 4.10.19.4 Limiting user input length
        5. 4.10.19.5 Form submission
        6. 4.10.19.6 Submitting element directionality
      20. 4.10.20 APIs for the text field selections
      21. 4.10.21 Constraints
        1. 4.10.21.1 Definitions
        2. 4.10.21.2 The constraint validation API
        3. 4.10.21.3 Security
      22. 4.10.22 Form submission
        1. 4.10.22.1 URL-encoded form data
        2. 4.10.22.2 Plain text form data
    11. 4.11 Interactive elements
      1. 4.11.1 The details element
      2. 4.11.2 The summary element
      3. 4.11.3 The command element
      4. 4.11.4 The menu element
        1. 4.11.4.1 Introduction
        2. 4.11.4.2 Context menus
      5. 4.11.5 Commands
      6. 4.11.6 The dialog element
        1. 4.11.6.1 Anchor points
    12. 4.12 Links
      1. 4.12.1 Introduction
      2. 4.12.2 Links created by a and area elements
      3. 4.12.3 Downloading resources
      4. 4.12.4 Link types
        1. 4.12.4.1 Link type "alternate"
        2. 4.12.4.2 Link type "author"
        3. 4.12.4.3 Link type "bookmark"
        4. 4.12.4.4 Link type "help"
        5. 4.12.4.5 Link type "icon"
        6. 4.12.4.6 Link type "license"
        7. 4.12.4.7 Link type "nofollow"
        8. 4.12.4.8 Link type "noreferrer"
        9. 4.12.4.9 Link type "prefetch"
        10. 4.12.4.10 Link type "search"
        11. 4.12.4.11 Link type "stylesheet"
        12. 4.12.4.12 Link type "tag"
        13. 4.12.4.13 Sequential link types
          1. 4.12.4.13.1 Link type "next"
          2. 4.12.4.13.2 Link type "prev"
        14. 4.12.4.14 Other link types
    13. 4.13 Common idioms without dedicated elements
      1. 4.13.1 The main part of the content
      2. 4.13.2 Bread crumb navigation
      3. 4.13.3 Tag clouds
      4. 4.13.4 Conversations
      5. 4.13.5 Footnotes
  5. 5 Loading Web pages
    1. 5.1 Browsing contexts
      1. 5.1.1 Nested browsing contexts
        1. 5.1.1.1 Navigating nested browsing contexts in the DOM
      2. 5.1.2 Auxiliary browsing contexts
        1. 5.1.2.1 Navigating auxiliary browsing contexts in the DOM
      3. 5.1.3 Secondary browsing contexts
      4. 5.1.4 Browsing context names
    2. 5.2 The Window object
      1. 5.2.1 APIs for creating and navigating browsing contexts by name
      2. 5.2.2 Accessing other browsing contexts
      3. 5.2.3 Named access on the Window object
      4. 5.2.4 Browser interface elements
    3. 5.3 Origin
      1. 5.3.1 Relaxing the same-origin restriction
    4. 5.4 Sandboxing
    5. 5.5 Session history and navigation
      1. 5.5.1 The session history of browsing contexts
      2. 5.5.2 The History interface
      3. 5.5.3 The Location interface
    6. 5.6 Browsing the Web
      1. 5.6.1 History traversal
      2. 5.6.2 Unloading documents
    7. 5.7 Offline Web applications
      1. 5.7.1 Introduction
        1. 5.7.1.1 Event summary
      2. 5.7.2 The cache manifest syntax
        1. 5.7.2.1 Some sample manifests
        2. 5.7.2.2 Writing cache manifests
      3. 5.7.3 Application cache API
      4. 5.7.4 Browser state
  6. 6 Web application APIs
    1. 6.1 Scripting
      1. 6.1.1 Introduction
      2. 6.1.2 Events
        1. 6.1.2.1 Event handlers on elements, Document objects, and Window objects
    2. 6.2 Base64 utility methods
    3. 6.3 Timers
    4. 6.4 User prompts
      1. 6.4.1 Simple dialogs
      2. 6.4.2 Printing
      3. 6.4.3 Dialogs implemented using separate documents
    5. 6.5 System state and capabilities
      1. 6.5.1 The Navigator object
        1. 6.5.1.1 Client identification
        2. 6.5.1.2 Custom scheme and content handlers
        3. 6.5.1.3 Manually releasing the storage mutex
      2. 6.5.2 The External interface
  7. 7 User interaction
    1. 7.1 The hidden attribute
    2. 7.2 Inert subtrees
    3. 7.3 Activation
    4. 7.4 Focus
      1. 7.4.1 Sequential focus navigation and the tabindex attribute
      2. 7.4.2 Document-level focus APIs
      3. 7.4.3 Element-level focus APIs
    5. 7.5 Assigning keyboard shortcuts
      1. 7.5.1 Introduction
      2. 7.5.2 The accesskey attribute
    6. 7.6 Editing
      1. 7.6.1 Making document regions editable: The contenteditable content attribute
      2. 7.6.2 Making entire documents editable: The designMode IDL attribute
      3. 7.6.3 Best practices for in-page editors
      4. 7.6.4 Editing APIs
      5. 7.6.5 Spelling and grammar checking
    7. 7.7 Drag and drop
      1. 7.7.1 Introduction
      2. 7.7.2 The drag data store
      3. 7.7.3 The DataTransfer interface
        1. 7.7.3.1 The DataTransferItemList interface
        2. 7.7.3.2 The DataTransferItem interface
      4. 7.7.4 The DragEvent interface
      5. 7.7.5 Events summary
      6. 7.7.6 The draggable attribute
      7. 7.7.7 The dropzone attribute
  8. 8 The HTML syntax
    1. 8.1 Writing HTML documents
      1. 8.1.1 The DOCTYPE
      2. 8.1.2 Elements
        1. 8.1.2.1 Start tags
        2. 8.1.2.2 End tags
        3. 8.1.2.3 Attributes
        4. 8.1.2.4 Optional tags
        5. 8.1.2.5 Restrictions on content models
        6. 8.1.2.6 Restrictions on the contents of raw text and RCDATA elements
      3. 8.1.3 Text
        1. 8.1.3.1 Newlines
      4. 8.1.4 Character references
      5. 8.1.5 CDATA sections
      6. 8.1.6 Comments
    2. 8.2 Named character references
  9. 9 The XHTML syntax
  10. 10 Obsolete features
    1. 10.1 Obsolete but conforming features
    2. 10.2 Non-conforming features
  11. 11 IANA considerations
    1. 11.1 text/html
    2. 11.2 multipart/x-mixed-replace
    3. 11.3 application/xhtml+xml
    4. 11.4 application/x-www-form-urlencoded
    5. 11.5 text/cache-manifest
    6. 11.6 web+ scheme prefix
  12. Index
    1. Elements
    2. Element content categories
    3. Attributes
    4. Element Interfaces
    5. All Interfaces
    6. Events
  13. Index of terms
  14. References
  15. Acknowledgements