<docDate> is not allowed in a
<docAuthor> is allowed in
It could be very interesting that an application could safely rely on <docDate> and <docAuthor> to have metadatas about a <div> which could be for example a conference or a chapter of a book under another director. It’s important to not allow <docDate> and <docAuthor> everywhere, so that meaning could be lost.
It seems good to keep parallel behaviours between <docDate> and <docAuthor>, as blocks in a title page (model.titlepagePart, model.pLike.front), it could be nice to also allow them as inline elements in the blocks <byline> and <dateline>.
The distinction of <byline> and <dateline> is clear, but some editors do not follow it strictly, so that a <docDate> could appears in <byline>
« by John Doe, the 12 of july »
or a <docAuthor> in a <dateline>
« London, 1913, John Doe »