IMC, each area has a Kn(Local), based on culture, population size, land size, etc. I never use the phrase "Knowlege (Local)" in-game -- I always refer to the specific place.
Kn(Luxoria) applies to a single large kingdom (about the size of California) and the outlands around it. The land area includes three major metropolitan areas, twenty medium-sized cities, and four City-state sized colonies (one extraplanar).
Kn(Blood Sea) applies to a bunch of island kingdoms, about the size of the Caribbean. Three medium-sized Kingdoms (one metropolis each), twenty minor states.
Kn(Gehenna) applies to the lower plane of the same name, and it's how I differentiate knowlege about the critters from a plane (which is Kn(Planes)) and the politics of that plane. The PCs have spent some time there (not quite voluntarily) and have had the opportunity to learn a bit about the politics & players there.
-- N