From HTML WG Wiki
Notes for the ISSUE-41 CP
The other two Change Proposals
What are the use-cases for allowing authors to create proprietary (but validating) HTML elements?
http://lists.w3.org/Archives/Public/public-html/2009Oct/0820.html http://lists.w3.org/Archives/Public/public-html/2008Apr/0205.html http://lists.w3.org/Archives/Public/public-html/2008May/0552.html http://lists.w3.org/Archives/Public/public-html/2008May/0182.html http://wiki.whatwg.org/wiki/New_Vocabularies http://wiki.whatwg.org/wiki/Extensions http://wiki.whatwg.org/wiki/New_Vocabularies_Solution
Hixie: "I have been unable to come up with a generic syntax for vocabulary extension that looks (even slightly) like XML and that would actually work in practice on the Web"
Important for extensions to be able to survive syndication:
Feasability of CSS-like <-vendor-foo>:
class="" is for use as an author-level extension syntax.
A bunch of potential use-cases and Henri's replies to them:
Microdata adds extensibility points to HTML:
Comments on the "adding new features to the core Web language without peer review" use-case:
http://lists.w3.org/Archives/Public/public-html/2008Aug/0160.html http://lists.w3.org/Archives/Public/public-html/2008Aug/0054.html http://lists.w3.org/Archives/Public/public-html/2008Aug/0022.html http://lists.w3.org/Archives/Public/public-html/2008Aug/0006.html
Disambiguation isn't a real problem:
Issue 41 is about enabling decentralized parties to create their own languages.
DOM consistency and : in names
Sam: "Suffice it to say that as long as the answer works out that there is no mechanism by which independent parties can define new elements, I will never be satisfied."
Prefix indirection is bad, mmmkay?
http://lists.w3.org/Archives/Public/public-html/2008Jul/0453.html http://lists.w3.org/Archives/Public/public-html/2008Jul/0365.html http://lists.w3.org/Archives/Public/public-html/2008Jul/0363.html http://lists.w3.org/Archives/Public/public-html/2008Jul/0357.html