[whatwg] Attribute for holding private data for scripting

[Sam Ruby]

Anne van Kesteren wrote:
> On Tue, 10 Apr 2007 22:41:12 +0200, Sam Ruby <rubys at intertwingly.net> 
> wrote:
>> How so?
> 
> I missed the part where you wanted to change existing HTML parsers. I 
> thought Hixie pointed out earlier (by means of examples) why we can't 
> have namespace parsing in HTML. I suppose we can discuss it again...

It is a recurring pattern.  The first instance was "we can't allow 
trailing slashes in tags", which was followed up by a carefully crafted 
and narrow set of exceptions, which was met with "that works" and was 
adopted.

So... while it is clearly true the full extent of XML namespames will 
never be supported in HTML5 (and for good reason), namespace qualified 
attributes allow extensibility in ways that prevent collisions.

One of the first questions that would need to be answered: are there any 
existing documents on the web which would be broken if the name placed 
into the DOM for attributes with names containing a colon, with an 
apparent prefix, and one that matched an enclosing xmlns: declaration 
were to be changed?

- Sam Ruby