RVSM

Airspace between FL290 and FL410 (inclusive) is designated as reduced vertical separation minimums (RVSM) airspace. In the real world, aircraft must meet certain altimeter accuracy requirements in order to operate in this airspace. On Vatsim, we presume all aircraft are equipped for flight within RVSM airspace.

{Reference: FAAO 7110.65 2-1-28}