I would agree with wildcard but basicly you would have to see and know what the builder you plan to use considers as a mx or trail or drag port
unfortunatly for the patron every one seems to have a different idea of what name should justify the port layout ,so theres no universal reference point although it is generally considered a trai lport should obviously focus on low- midrange for response broad power for hill climbs technical stuff buzzing around the woods ..and a mx port should come on strong around say 5-6 ,000rpms to come out of the corners and and still have decent lowend torque for holeshots and short bursts, its kinda crazy some builders drag ports ive seen look like my trail porting ,this is where a customer/ builder realtionship is important so it performs correctly for the application