[css-style-attr][css3-namespace] Namespace prefixes in style attributes?

Hi,

With the new, generalized attr() function from css3-values, CSS 
qualified names can appear not only in selectors but also in property 
declarations. These qualified names depend on prefix declared in 
@namespace rules.

What prefix declarations should apply to style attributes? For example:

<foo xmlns:xlink="http://www.w3.org/1999/xlink"
      xlink:href="the_target.bar"
      style="content: '[' attr(xlink|href) ']';"/>

I see two possibilities:

* None. As if the declarations were in an implicit stylesheet that has
   no @namespace rule.
* If the host language has namespace prefixes (like XML does), "inherit"
   the namespace declarations from the element.

Either are fine IMO, but this should be defined somewhere.

-- 
Simon Sapin