Leland:
I have to add a personal comment here:
As an EC, doing primarily comm work I always had support wires installed for lay-in's, irregardless of 'code'.
The hassles of the Elec Insp passing 'ceiling, and then the Bldg or Fire Inspector leaving a red tag was a pain. This was a pain from way back when a lay-in was made slightly heverier then a empty six pack of alum cans.
Most of the comm guys here do install wires, although I cannot mandate it thru NEC. Sometimes more is better.
