HTML5 (including next generation additions still
in development)
Draft Standard — 7 April 2010
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Multiple-page version:
http://whatwg.org/html5
One-page version:
http://www.whatwg.org/specs/web-apps/cu
ent-work/
PDF print versions:
A4: http://www.whatwg.org/specs/web-apps/cu
ent-work/html5-a4.pdf
Letter: http://www.whatwg.org/specs/web-apps/cu
ent-work/html5-letter.pdf
Version history:
Twitter messages (non-editorial changes only): http://twitter.com/WHATWG
Commit-Watchers mailing list: http://lists.whatwg.org/listinfo.cgi/commit-watchers-whatwg.org
Interactive Web interface: http://html5.org/tools/web-apps-tracke
Subversion interface: http://svn.whatwg.org/
Issues:
To send feedback: whatwg@whatwg.org
To view and vote on feedback: http://www.whatwg.org/issues/
Editor:
Ian Hickson, Google, ian@hixie.ch
© Copyright 2004-2010 Apple Computer, Inc., Mozilla Foundation, and Opera Software ASA.
You are granted a license to use, reproduce and create derivative works of this document.
Abstract
This specification evolves HTML and its related APIs to ease the authoring of Web-based applications. The most recent
additions include a devicep401 element to enable video conferencing, as well as all the features added as part of the
earlier HTML5 effort.
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Status of this document
This is a work in progress! This document is changing on a daily if not hourly basis in response to comments and as
a general part of its development process. Comments are very welcome, please send them to whatwg@whatwg.org.
Thank you.
Outstanding feedback is tracked; all e-mails sent to the list above receive a reply. The level of outstanding feedback is
charted to allow progress to be evaluated.
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 call for implementations should
join the WHATWG mailing list and take part in the discussions.
This specification is intended to replace (be the new version of) what was previously the HTML5, HTML4, XHTML1, and
DOM2 HTML specifications.
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Table of contents
1 Introduction..................................................................................................................................................16
1.1 Is this HTML5?............................................................................................................................16
1.2 Background................................................................................................................................16
1.3 Audience....................................................................................................................................16
1.4 Scope.........................................................................................................................................17
1.5 History.......................................................................................................................................17
1.6 Design notes..............................................................................................................................18
1.6.1 Serializability of script execution ............................................................................18
1.6.2 Compliance with other specifications......................................................................18
1.7 HTML vs XHTML.........................................................................................................................19
1.8 Structure of this specification....................................................................................................19
1.8.1 How to read this specification.................................................................................20
1.8.2 Typographic conventions ........................................................................................20
1.9 A quick introduction to HTML.....................................................................................................20
1.10 Conformance requirements for authors...................................................................................22
1.10.1 Presentational markup..........................................................................................23
1.10.2 Syntax e
ors ........................................................................................................23
1.10.3 Restrictions on content models and on attribute values.......................................25
1.11 Recommended reading............................................................................................................27
2 Common infrastructure ................................................................................................................................28
2.1 Terminology ...............................................................................................................................28
2.1.1 Resources ...............................................................................................................28
2.1.2 XML.........................................................................................................................28
2.1.3 DOM trees...............................................................................................................29
2.1.4 Scripting..................................................................................................................29
2.1.5 Plugins ....................................................................................................................29
2.1.6 Character encodings...............................................................................................30
2.2 Conformance requirements .......................................................................................................30
2.2.1 Dependencies.........................................................................................................33
2.2.2 Extensibility ............................................................................................................34
2.3 Case-sensitivity and string comparison.....................................................................................35
2.4 Common microsyntaxes ............................................................................................................36
2.4.1 Common parser idioms...........................................................................................36
2.4.2 Boolean attributes ..................................................................................................37
2.4.3 Keywords and enumerated attributes.....................................................................37
2.4.4 Numbers .................................................................................................................37
2.4.4.1 Non-negative integers..........................................................................37
2.4.4.2 Signed integers....................................................................................38
2.4.4.3 Real numbers.......................................................................................38
2.4.4.4 Percentages and lengths......................................................................40
2.4.4.5 Lists of integers....................................................................................41
2.4.4.6 Lists of dimensions...............................................................................42
2.4.5 Dates and times......................................................................................................43
2.4.5.1 Months .................................................................................................43
2.4.5.2 Dates....................................................................................................44
2.4.5.3 Times ...................................................................................................45
2.4.5.4 Local dates and times ..........................................................................46
2.4.5.5 Global dates and times ........................................................................46
2.4.5.6 Weeks...................................................................................................48
2.4.5.7 Vaguer moments in time......................................................................49
2.4.6 Colors......................................................................................................................50
2.4.7 Space-separated tokens..........................................................................................52
2.4.8 Comma-separated tokens.......................................................................................53
2.4.9 References..............................................................................................................54
2.4.10 Media queries .......................................................................................................54
2.5 URLs ..........................................................................................................................................54
2.5.1 Terminology ............................................................................................................54
2.5.2 Dynamic changes to base URLs..............................................................................56
2.5.3 Interfaces for URL manipulation..............................................................................56
2.6 Fetching resources.....................................................................................................................58
2.6.1 Protocol concepts....................................................................................................60
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