I'm having trouble finding references. When I'm done typing this I'm going to go
https://www.electrical-contractor.net/the_store/NEC_Code2002.htm?RCKeepShoping=Keep+Shopping

and get myself the 99'-2002 handbook on CD rom.

I've been told no electric on the grid, only power directly associated with grid mounted fixtures can be supported by the grid, power can be supported as long as it has dedicated pencil rods gong to it etc., etc.

Is there an NEC reference or is this a building code issue. I'm sure it is also a local issue.