Van Richten's Guide to the Mists (Book)

There is some question as to whether this work should be consider canon, less for the manner of its release, than for its very topic which designers had made an express decision to leave in obscurity. Additionally, it has been pointed out that oubilettes violate the existing topological rules of the the Demiplane (i.e. anything that is carved out of the Mists has a Darklord).