While xlink:title and xlink:type="title" offer great flexibility in
allowing markup to serve in a descriptive role, I believe that it might
be even more flexible to add xlink:titlerole and xlink:type="titlerole"
to indicate that a particular xlink:title attribute or a particular
element, respectively, belonged to a particular category of descriptive
title. For example, one might use an IRI as follows:
Perhaps some other attribute such as xlink:titletype could be added to
indicate other means of detecting the titlerole, such as by the presence
of particular markup (e.g., that if present on a <label> element, it
should be treated as such-and-such a titlerole, etc). This way popular
titleroles might lead to a particular default display within generic
I believe such options can allow for XLink titles to be displayed by
various applications, some fairly generic as well as specific.