Is there a good way to make an <idno> a link? <ref> isn't allowed inside it. It has no @target.

The Example includes
<idno type="DOI"></idno>
<idno type="URL"></idno>
but I don't see how to tag those as URLs.

For non-web addresses, it could be nice to include a link to the cataloging system, something like
<idno type="Wing" xml:base="" target="search?bibnum=C695">C695</idno>

-- John
John P McCaskey PhD [log in to unmask]
Brown University
Political Theory Project
Stanford University
History & Philosophy of Science
Harvard University
I Tatti Renaissance Library
Stevens Institute of Technology
College of Arts & Letters