Important question from Accessibility SC

The accessibility committee has a question
that it wishes to pose to the full TC.

There are several places where ODF currently
lacks a way to specify an alternative textual description of a non-textual
object.  In such cases, we could either invent a new tag or reuse
an existing tag in what seems (to us) to be a reasonable way.  In
particular, we're wondering whether or not we can simply use draw:name,
svg:desc, and office:name for such a purpose.  Would the TC recommend
doing so, or would it be preferable for us to create a new tag such as
svg:title?  Obviously either approach will work, but we aren't sure
which is better.  All opinions are invited.  -- Nathaniel