<bibl> has several potentially useful elements available to it,
which don't seem to be available in <biblStruct>:
These are certainly needed when citing projects, or multimedia publications which have distributors. <distributor> is a member of model.imprintPart, but that is not really useful if the document being cited is an online publication. I propose that:
<distributor be added to model.respLike, which already contains <principal>, <funder> and <sponsor>; and
model.respLike be added to <analytic>, <monogr> and <series>, so that these elements are available in <biblStruct> citations.