AIRSPACE INFORMATION (Continued) NAVIGATIONAL AND PROCEDURAL INFORMATION Low and High  Charts Canada Only CYA - Advisory Area CYD - Danger Area CYR - Restricted Area Caribbean Only D - Danger Area In the Caribbean, the first two letters represent the  country code, i.e. (MY) Bahamas, (MU) Cuba 18,000’ MSL to FL280 RVSM Levels FL290 to FL410  FL430 and above No VFR or VFR On Top  authorized above FL285 in  RVSM airspace. VFR or VFR On Top add 500’ No VFR flights within  Class A Airspace above 3000’ AGL unless otherwise authorized 88 All courses are magnetic. IFR within controlled airspace as assigned by ATC  VFR above 3000’ AGL unless otherwise  authorized by ATC. IFR outside controlled airspace. IFR within controlled airspace as  assigned by ATC. ALL courses are magnetic. Cruising Altitudes - High Charts - U.S. Only Cruising Altitudes - Low Charts - U.S. Only Special Use Airspace - Canada & Caribbean FAA Chart Users’ Guide - IFR Enroute Symbology