CPV code 63700000 designates Support services for land, water and air transport in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
63700000 sits under 63000000 (Supporting and auxiliary transport services; travel agencies services) and groups 3 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.