HTML+RDFa 1.1 (original) (raw)

A.1 History

This section is non-normative.

In early 2004, Mark Birbeck published a document named "RDF in XHTML" via the XHTML2 Working Group wherein he laid the groundwork for what would eventually become RDFa (The Resource Description Framework in Attributes).

In 2006, the work was co-sponsored by the Semantic Web Deployment Work Group, which began to formalize a technology to express semantic data in XHTML. This technology was successfully developed and reached consensus at the W3C, later published as an official W3C Recommendation. While HTML provides a mechanism to express the structure of a document (title, paragraphs, links), RDFa provides a mechanism to express the meaning in a document (people, places, events).

The document, titled "RDF in XHTML: Syntax and Processing" [XHTML-RDFA], defined a set of attributes and rules for processing those attributes that resulted in the output of machine-readable semantic data. While the document applied to XHTML, the attributes and rules were always intended to operate across any tree-based structure containing attributes on tree nodes (such as HTML4, SVG and ODF).

While RDFa was initially specified for use in XHTML, adoption by a number of large organizations on the Web spurred RDFa's use in non-XHTML languages. Its use in HTML4, before an official specification was developed for those languages, caused concern regarding document conformance.

Over the years, the members of the RDFa Task Force had discussed the possibility of applying the same attributes and processing rules outlined in the XHTML+RDFa specification to all HTML family documents. By design, the possibility of a unified semantic data expression mechanism between all HTML and XHTML family documents was squarely in the realm of possibility.

An RDFa Working Group was created in 2010 to address the issues concerning multiple language implementations of RDFa. The XHTML+RDFa document was split into a base specification, called RDFa Core 1.1 [RDFA-CORE], and _thin_specifications that layer above RDFa Core 1.1. The XHTML+RDFa 1.1 specification [XHTML-RDFA] is an example of such a thin specification. This document, also a thin specification, is targeted at HTML4, HTML5 and XHTML5.

This document describes the extensions to the RDFa Core 1.1 specification that permits the use of RDFa in all HTML family documents. By using the attributes and processing rules described in the RDFa Core 1.1 specification and heeding the minor changes in this document, authors can generate markup that produces the same semantic data output in HTML4, HTML5 and XHTML5.

A.2 Change History

This section is non-normative.

2009-10-15: First version of the RDFa for HTML4, HTML5 and XHTML5.

2010-03-04: Updated HTML5 coercion to Infoset rules, preservation of namespaces in Infoset and DOM2-based processors, clarifying how to extract RDFa attributes via Infoset, how to extract RDFa attributes via DOM2.

2010-05-02: Inheritance of basic processing rules from RDFa 1.1 [RDFA-CORE], instead of XHTML+RDFa 1.0 [RDFA-SYNTAX], inclusion of the HTML Default Vocabulary Terms, inclusion of a HTML 4.01 + RDFa 1.1 DTD for validation purposes.

2010-06-24: Inheritance of basic processing rules from RDFa 1.1 [RDFA-CORE], instead of XHTML+RDFa 1.0 [RDFA-SYNTAX], inclusion of the HTML Default Vocabulary Terms, added HTML 4.01 + RDFa 1.1 DTD for validation purposes, added normative definition of @version attribute.

2010-10-19: Removal of @version attribute, migrated HTML Vocabulary Terms to RDFa Profile document, added statement to send comments to the HTML WG bug tracker.

2011-01-11: Removed decentralized extensibility issue markers, added DOM Level 1 prefix mapping extraction algorithm.

2011-04-05: Moved all xmlns: rules into a section titled Backwards Compatibility and brought spec in-line with latest RDFa Core 1.1 spec.

2011-05-12: Generated Last Call document, no substatitive changes.

2011-12-30: Addition of normative dependency for RDFa Lite 1.1. Addition of rules to allow meta and link elements in flow and phrasing content as long as they contain at least one RDFa-specific attribute. Added support for datetime and value processing.

2012-03-10: Clarification of where each RDFa attribute is allowed to be used. Feature at risk warning for HTML4+RDFa DTD-based validation.

2012-09-10: Publishing control of the HTML+RDFa document is handed over from the HTML WG to the newly re-chartered RDFa WG. DTD-based validation is removed from the specification.

A.3 Acknowledgments

This section is non-normative.

At the time of publication, the members of the RDF Web Applications Working Group were:

Ivan Herman (staff contact), Shane McCarron, Gregg Kellogg, Niklas Lindström, Steven Pemberton, Manu Sporny (chair), Ted Thibodeau, and Stéphane Corlosquet.

At the time of publication, the members of the HTML Working Group were:

Colin Aarts, Miller Abel, D.R.Imanuel Abromeit, Robert Accettura, Chris Adams, Ben Adida, Arihant Agarwal, yael aharon, Jim Allan, Kazuyuki Ashimura, Tab Atkins Jr., Stephen Axthelm, Mark Baker, Christopher Bank, Bogdan Baraszkiewicz, Gary Barber, David Baron, Adam Barth, Aaron Bassett, Adrian Bateman, Matthias Bauer, Johannes Behr, John-Mark Bell, Robin Berjon, Arve Bersvendsen, Levent Besik, David Bills, Mark Birbeck, David Bolter, Anders Bondehagen, Marco Bonetti, Glenn Bookout, Sierk Bornemann, Denis Boudreau, Ben Boyle, River Brandon, Judy Brewer, Dan Brickley, Per-Erik Brodin, Thomas Broyer, Don Brutzman, Craig Buckler, Dick Bulterman, Daniel Burnett, Noel Bush, Andrew Buzzell, Craig Cadwallader, Sally Cain, Ben Caldwell, Brian Campbell, Carlos Cardona, Maurice Carey, Eric Carlson, Laura Carlson, Gavin Carothers, Wayne Carr, Tomas Caspers, James Cassell, Tantek Çelik, Namachivayam Chelladurai, David Child, Wendy Chisholm, David Choi, wu chou, Edward Cianci, Michaeljohn Clement, Richard Conyard, Michael Cooper, Paul Cotton (chair), Chris Cressman, Brendan Cullen, Joseph D'Andrea, Mohammed DADAS, Deborah Dahl, Erik Dahlström, David Dailey, Will Daniels, Ivan De Marino, Tommaso Donnarumma, Chris Double, John Drinkwater, Marc Drumm, Mark DuBois, Karl Dubost, Andrew Duck, Clair Dunn, Henrik Dvergsdal, Dean Edridge, Anand Samuel Edwin, Eric Eggert, S Emerson, Ivan Enderlin, Rob Ennals, Jean-Pierre EVAIN, Steve Faulkner, Andrew Fedoniouk, Alexey Feldgendler, Alejandro Fernandez, Ian Fette, Roy Fielding, Markus Fischer, David Fisher, Nick Fitzsimons, Mark Foladare, John Foliot, Kelly Ford, Jason Fowler, Geoff Freed, Matthew Freels, Steve Gabrio, Mike Ganner, Patrick Garies, Olivier Gendrin, Giovanni Gentili, Dragos Georgita, Dimitri Glazkov, Daniel Glazman, Eliot Graff, James Graham, Aryeh Gregor, Chris Griego, Jonathan Griffin, Guillaume Guérin, Jon Gunderson, Lars Gunther, Raghavan Gurumurthy, Markku Hakkinen, Marcin Hanclik, Matt Harris, Chris Hay, Sean Hayes, Ian Hickson, Thomas Higginbotham, Krijn Hoetmer, Laurens Holst, Mikko Honkala, Tobias Horvath, Peter Howkins, Raul Hudea, Dale Hudjik, Jon Hughes, Lachlan Hunt, David Hyatt, David Håsäther, Eihab Ibrahim, Kunter Ilalan, Toby Inkster, Patrick D F Ion, Erik Isaksen, Richard Ishida, Moto Ishizawa, Yudai Iwasaki, Dean Jackson, Justin James, Arthur Jennings, Arne Johannessen, Kenny Johar, Sam Johnston, Sam Johnston, Doug Jones, Wilhelm Joys Andersen, Philip Jägenstedt, Susanne Jäger, Yehuda Katz, Jeremy Keith, Serge K. Keller, John Kemp, Kazuhito Kidachi, Don Kiely, Dowan Kim, Sebastian Kippe, Martin Kliehm, Egor Kloos, Graham Klyne, Justin Anthony Knapp, Masatomo Kobayashi, Marcel Koeppen, Jirka Kosek, Anssi Kostiainen, Lee Kowalkowski, Michael Kozakewich, Maxim Kozhuh, Peter Krantz, Keith Krieger, Kris Krueger, Mayank Kumar, Michael Köller, Jonatan Lander, Lucas Larson, Bruce Lawson, Josh Lawton, Nicolas LE GALL, Chasen Le Hara, Philippe Le Hégaret, Jane Lee, Kangchan Lee, WonSuk Lee, Niels Leenheer, Dean Leigh, Travis Leithead, Gez Lemon, Kornel Lesinski, aurélien levy, Scott Lewis, Li Li, Danny Liang, Jake Liddell, Håkon Wium Lie, Jedi Lin, Andy Lintner, Feng Liu, Jianjun Liu, Robert Love, Guillaume Ludwig, Andrew Maben, Shefik Macauley, Matthew MacKenzie, Krzysztof Maczynski, Vilem Malek, Murray Maloney, Jatinder Mann, Gabriel Mansour, Zhihong Mao, Bilgehan Maras, Chris Marrin, Robert Marshall, Andrew Martin, Alfonso Martínez de Lizarrondo, Luca Mascaro, Larry Masinter, Bill Mason, Matthew May, Cena Mayo, Charles McCathieNevile, Cameron McCormack, Martin McEvoy, Benjamin Meadowcroft, Shawn Medero, Reinier Meenhorst, Jens Meiert, Jakob Melander, Markus Mielke, Ben Millard, Mark Miller, Ryan Mitchell, Katsuhiko Momoi, Stefan More, Terry Morris, Thomas Morris, Daniel Morrison, Simon Myers, Stuart Myles, Marco Neumann, Sharon Newman, Tom Nguyen, Andrey Nikanorov, Jer Noble, Andrew Norman, Joshue O Connor, Robert O'Callahan, Edward O'Connor, Matt Obee, Frank Olivier, Ryan Orr, Debi Orton, Kulanthaivel Palanichamy, Frank Palinkas, Soohong Daniel Park, Sylvain Pasche, Chris Pearce, Brian Peppler, Ariel Pérez, Adele Peterson, Silvia Pfeiffer, Simon Pieters, Benoit Piette, Thomas Pike, Gabriel Pizzorno, Andrew Polk, Andrei Polushin, Pasquale Popolizio, Harri Porten, Alexey Proskuryakov, Michael Puls II, Juan Quemada, T.V. Raman, Andrew Ramsden, Arun Ranganathan, Marco Ranon, Matthew Ratzloff, Matthew Raymond, Ron Reisor, Daniel Renfer, Julian Reschke, Cyra Richardson, Ole Riesenberg, Anders Ringqvist, Adam Roben, Alex Robinson, Jude Robinson, Leonard Rosenthol, Gregory Rosmaita, Tony Ross, Steven Roussey, Sam Ruby (chair), Pietro Russo, Weston Ruter, Monikandan S, Lucas Sa, Rene Saarsoo, Sajid Saiyed, Janina Sajka, joaquin Salvachua, satish sangaru, Samuel Santos, Sorin Sbarnea, Daniel Schattenkirchner, Doug Schepers, Kai Scheppe, Christian Schmidt, Sebastian Schnitzenbaumer, Christopher Schroeder, Richard Schwerdtfeger, Gavin Sharp, Cynthia Shelly, Jonas Sicking, Andrew Sidwell, Leif Halvard Silli, David Singer, Henri Sivonen, Brian Skahan, Kenneth Sklander, Dan Smith, Dylan Smith, Michael(tm) Smith (staff contact), Sam Sneddon, Gnanasekar S Somanathan, Manu Sporny, Elliott Sprehn, Maciej Stachowiak (chair), Vicki Stanton, Hallvord Steen, Johnny Stenback, Robert Stern, Peter Stewart, Stephen Stewart, Andrew Stibbard, Bruce Stockwell, Motti Strom, Oli Studholme, Mihai Sucan, Bryan Sullivan, Marat Tanalin, Mike Taylor, Philip Taylor, Sander Tekelenburg, Shane Thacker, Nik Thierry, Morten Tollefsen, Dominik Tomaszuk, Dzung Tran, Monika Trebo, Mark Turnage, Jason Turnbull, Scott Turner, Michael Turnwall, Matthew Turvey, Asbjørn Ulsberg, Wesley Upchurch, Ojan Vafai, Erik van Kempen, Anne van Kesteren, Sander van Lambalgen, Charl van Niekerk, Tim van Oostrom, Christopher Varley, Jean-Charles Verdié, John Vernaleo, Scott Vesey, Sigbjørn Vik, Laurent Vilday, Kent Villard, Jace Voracek, David Voth, Vladimir Vukicevic, Johnson Wang, Martijn Wargers, Jonathan Watt, Kyle Weems, Samuel Weinig, Ian Wessman, Ben West, Jason White, Michael Whitley, Joe Williams, Andrew Wilson, Chris Wilson, Doug Wright, Han Xu, Mateo Yadarola, Masataka Yakura, Channy Yun, Michael Zajac, Boris Zbarsky, Milan Zoufal, Michael zur Muehlen