location tag and removable media tags

Hi all,
 Some discussion came up about the <location> tag and removable media.

For removable media there is some interest in generating one set of
metadata for the first media of N.

In the case of cds - 1/4 cds is not uncommon anymore.

Would it be reasonable for the location tag to include a media
identifier attribute so a tool reading the metadata would know which
piece of media to find the metadata on?

Thoughts?

-sv