A:
The term for cables that are intended to go behind walls is "Plenum Rated" or "Riser Rated". There are several sub types of in-wall cable ratings, they generally refer to whether they are in an air-handling area or not. You want to use a cable that is CMR (riser rated) if you are behind a wall, and CL2 or "Plenum Rated" if it is behind a wall or ceiling and in an air handling area (some AC systems use the area above a ceiling as an air return). Plenum rated cable is much more expensive. Also, I see you are in Canada- CL2 is equivalent to FT4 rating in Canada, while CMP is equivalent to FT6.