This is the CodeSystem that contains all the codes in X12 Ambulance Transport Reason Codes (https://x12.org/codesystem.x12.org/ambulance-transport-reason-codes) and X12 Ambulance Transport Reason Codes (https://x12.org/codesystem.x12.org/ambulance-transport-reason-codes). E.g. what you have to deal with if you get resources containing codes in either of them