(i.e. the type of landscapes that can be shuffled into the randomizer deck)
For the official expansions there's WELPs (Ways, Events, Landscapes, Projects), but this doesn't cover e.g. Asper's Edicts, and various other fan card mechanics.
So far the best I can come up with is LUWAKs (Landscapes Usable With Any Kingdom).
I've used the terms "independent landscapes" and "dependent landscapes" to make the distinction. The thought being that independent landscapes (WELPs, Edicts, Acts) appear regardless of what cards are in the Kingdom, while dependent landscapes (States, Artifacts, Boons, Hexes, Conditions) only appear as part of the design of a Kingdom card (or, in theory an Independent landscape), and thus their use is dependent on some other card/landscape.
This taxonomy became less useful with the release of Allies, as the eponymous type of landscape is somewhere in-between the two. They only appear when there is a Liaison, but no particular Ally is contingent on the presence of any particular Liaison. (And, if there is a Liaison, you still have to choose an Ally at random like you would a WELP).