Able to signal from the headend or hub so that only the particular specified subscriber's receiving the equipment is affected, enabling changes in the subscriber's level of service for premium channels/PPV etc.
Found on http://www.agbnielsen.net/glossary/glossaryQ.asp?type=alpha&jump=none
capable of being addressed. · (of a cable-TV system) capable of addressing or calling up any available channel. · (of stored information) capable of being accessed. Found on https://www.infoplease.com/dictionary/addressable