[CSS21] Normative reference to HTML4

CSS 2.1 currently has a normative reference to HTML4.  This is bad,
because HTML4 is obsolete and incorrect in some areas.  We should
instead be referencing HTML5, which actually specifies current
practice.

The specific issue that brought this up is the handling of attribute
selectors and the attr() function when an HTML boolean attribute is
minimized (that is, used without an explicit value in the markup, like
<audio controls>).  According to HTML4's DTD, the value of the
attribute is the name of the attribute, which is what should be used
for matching in attribute selectors and returned by the attr()
function.  In actual browsers, and as specified by HTML5, the value is
the empty string.

Officially, CSS2.1 should only have normative references to things in
PR or REC status.  In reality, of our 18 normative references, only 4
are PR or REC.  If we're okay with referencing those 14 other
documents, we should presumably be okay with referencing HTML5, which
is a much more mature and correct specification than HTML4 ever was,
regardless of its official classification in the W3C standards track.

~TJ

Received on Monday, 25 October 2010 22:07:42 UTC