Does this work?

This page is the single-dash version in the freelinking name:

http://ubl.xml.org/freelinking/invoice-test-profile-identifier-identifier

With a magic title:

Invoice. Test_ Profile Identifier. Identifier

The following link to the double-dash version in the freelinking name:

http://ubl.xml.org/freelinking/invoice--test--profile-identifier--identifier

With a magic title:

Invoice. Test_ Profile Identifier. Identifier