"Why do I need this. I bought the wire at my "Box" - it must meet code right?"

HAHAHAHA
Sorry, this made me laugh the moment I read it.

OK, seriously.

"Meet code"? What code?
Cable and wire are manufactured to a certain specification. THAT is meeting code. How you install it is another thing entirely. You can install perfectly legal and safe cable in a dangerous and non-complaint way.

I am not familiar with Canadian code on this so I cannot comment on the cable designations.

There are also specific cables that are "in-wall" rated. It has something to do with how the jacket of the cable reacts if the wire heats up due to excess current.

btw.....I am no professional, just read a lot of crap on the internet......

the cable must be marked FT-4 on it to be "in-wall",by code.

Not sure on the exact equivalent of CSA (Canadian Standards Association) FT-4 but I believe it is CL2 or CL3 - riser rated.

Basically, what it comes down to is that if a fire was to start at or near the in-wall cable, would the cable contribute to the fire spreading? With the correct insulation, as in in-wall rated, it would not substantially contribute. Between floors, in vertical walls, it should be riser rated. If the cable passes through air handling areas (very unlikely in residential) it must be plenum rated as well which means the fumes emitted are within specific toxic limits.

The silver/gold zip-cord type of speaker wire is hardly ever in-wall rated... but the good thing is that the proper in-wall speaker cable (CL2/CL3) is usually cheaper.

Coax, Video, Audio, Ethernet cables all must be in-wall rated as well.