I like to live dangerously :).

We have been pulling Liberty cable for so long that i have no idea what the rules are anymore. At AVS I suggested that a DIY guy get some 16/2 from the hardware store to test his gear out while he waited for speaker cable to be in stock at monoprice. Someone spotted that advice and brought the "zip cord aint legal" thing up and i was curious about it.

So far we know that it should be CL or CM rated to conform to NEC.

So does that mean its illegal to run this in wall or just that its not recommended? Are there specific circumstances that make it legal or not? Like high-rise vs single family home?