First, a suggestion I should have thought of previously: since
"isReferencedBy" was added as a type attribute option for relatedItem,
how about "isReviewOf"?
On government publications:
Not exactly my element (no pun intended), but can this new addition be
used to cover jurisdiction information for legal documents as well?
Perhaps you could make use of the elements from hierarchicalGeographic?
This link may or not be useful: