WD-webarch-20031209: Allowing extra attributes does change the conformance of existing data

Section 4.2.2, Story.  The text says that defining a new optional
"lang" attribute on a "film" element does not affect the conformance
of any existing data or software.  This isn't quite true: it changes
some invalid data (data with the undefined attribute "lang") into
valid data, and some non-conforming software (software which
erroneously accepts that invalid content) into conforming software.

The text is correct if, but only if, the universe of discourse is
restricted to valid data.

Received on Thursday, 4 March 2004 18:20:47 UTC