<label> appears to me to have an overly restrictive content model. For instance, it will not allow <bibl>. Different types of lists might often include in <label> elements an author/title, which could/should be wrapped in a <bibl>. Also, <soCalled> is allowed, but <q> is not. This seems wrong too. I'm using an odd, generated by the most recent version of Roma (as of today's date) using the more recent version of P5 (as of today's date).