These enumerations define the different types of navaids. They are each defined with a separate bit so that they may be bit-wise added together to form sets of nav-aid types.
NOTE: xplm_Nav_LatLon is a specific lat-lon coordinate entered into the FMS. It will not exist in the database, and cannot be programmed into the FMS. Querying the FMS for navaids will return it. Use XPLMSetFMSEntryLatLon to set a lat/lon waypoint.