CMX on NEC / UL (USA)-järjestelmän kaapelin tyyppimerkintä: C = Communications cable; M = Multipurpose rating (reading by usage, UNVERIFIED); X = Limited use (UNVERIFIED); CMX = Communications cable, limited use (residential and in raceway, outdoor-rated types). 300 V, 60 to 75 C. UL 444; NEC Article 800.