@xmlns ------ Native OWP: yes (for XHTML) Serialization Agnostic: no Decentralized Voc. Support: yes Clear AT contract: ?? Static provisioning: yes Simplicity: yes for end users/authors; no for script developers Appropriateness: yes (in XHTML) ---------------------------------------------------------------------- @hyphen space extension ----------------------- Native OWP: yes Serialization Agnostic: yes Decentralized Voc. Support: moderately (any value should be approved by the HTML5 WG to get the validators running) Clear AT contract: ?? Static provisioning: yes Simplicity: yes Appropriateness: yes (modulo the registration mechanism which gives the values the official blessing) ---------------------------------------------------------------------- RDFa/MD ------- Native OWP: yes Serialization Agnostic: yes Decentralized Voc. Support: yes Clear AT contract: ?? Static provisioning: yes Simplicity: unclear; many claim it is complicated, others disagree. MD is probably (marginally) simpler than RDFa Lite. RDFa Full is definitely more complex, but that may not be needed. Appropriateness: not really. The problem is what the subject is of a specific statement. If, say, an HTML page talks about an concert, RDFa/MD is typically used to add information about the _concert_, not about the
element holding the concert's description. Putting another way, RDFa/MD is appropriate to add information on a chapter as a whole, on the book as a whole, ie, a possible alternative to what DC terms are used for today. But may not be appropriate for, say, the 'intrinsic glossaries' use case. ---------------------------------------------------------------------- Custom Elements (using the upcoming Web Components Spec) -------------------------------------------------------- Native OWP: yes (eventually, when the specification is published in final form) Serialization Agnostic: yes Decentralized Voc. Support: yes Clear AT contract: At this moment probably not. ?? Static provisioning: Not really. A new element should be 'registered' through a simple script to be used properly, see, eg., http://www.html5rocks.com/en/tutorials/webcomponents/customelements/. That being said, the script may be very simple if the goal for the element is to be used by 'declarative' processes. Simplicity: yes for end users; moderately for script developers Appropriateness: yes ---------------------------------------------------------------------- @role ----- Native OWP: yes Serialization Agnostic: yes Decentralized Voc. Support: Unclear; new values should probably be registered through a mechanism that is still to be defined by the PF Working Group (or the HTML Working Group?) Clear AT contract: yes Static provisioning: yes Simplicity: yes Appropriateness: yes, modulo the registration issue above ---------------------------------------------------------------------- @class ------ Native OWP: yes Serialization Agnostic: yes Decentralized Voc. Support: yes Clear AT contract: probably Static provisioning: yes Simplicity: yes Appropriateness: Although the @class attribute is defined in very generic terms, ie, not only for styling, the practice is that it is mostly used for styling. As a consequence there is a major danger of value clash between styling and other purposes; as such, it is inherently error prone with very-difficult-to-find bugs. ---------------------------------------------------------------------- @data-* ------- Native OWP: yes Serialization Agnostic: yes Decentralized Voc. Support: yes Clear AT contract: ??? Static provisioning: yes Simplicity: yes, both for end users/authors and for Javascript programmers, for whom even specific interface methods exist to handle them smoothly Appropriateness: per HTML5 specification, no.