[selectors4] List [xml:lang] and [xmlns] as selectors that do not work in XML

The section on ‘Attribute selectors and namespaces’ says: [1] 

]]
   [|att] { color: green }
    [att] { color: green }
      [ … snip … ]
   The last two rules are equivalent and will match only elements
   with the attribute att where the attribute is not in a namespace.
[[

Hence, these rules would not work in a namespace aware XML parser:

 	   [xmlns] { color: green }
	[xml:lang] { color: green }

Proposal: Please add a note/info that mentions @xml:foo and @xmlns as 
examples of common attributes that cannot, when occurring in a XML 
document, be styled with a simple [att]{} selector. It helps authors to 
understand the concept if they see an actual, non-theoretical, example.

[1] http://dev.w3.org/csswg/selectors4/#attrnmsp

-- 
leif halvard silli