[SU11 Beta] Taxipath - requirements for vehicles to use them?

I am finding that taxipath with taxi designations (A< B C … etc) and without
taxi designations will not have any vehicles follow the path to a vehicle
parking spot. It seems only a vehicle parking attached to a taxipath set to
Vehicle works. The SDK has said that vehicles may use any taxipath. If so what
ae the specifics required and can they be put into the SDK docs.