Here's the dilemna: 300-4d of the NEC requires protection of NM sheathed cable and MC cable within 1/1/4" of the edge of a stud where the conductors are LIKELY to be penetrated. The local AHJ's are requiring nail plates behind the conductors on a 3-1/2" stud wall where the non-metallic sheathed cable enters a plastic box in a typical residence. I hope you got that. In other words, not only where a cable is perpindicular to a stud and the clearance is less than 1-1/4", but also where the cable enters the box, because this space could be as little as 1/4". The inspectors are reading the intent in the 99 handbook and not the literal sense of the word. Is anybody in the country having to protect the back of a box where the cable enters it with nail plates and does anybody agree with this? Please respond to this. Florida enforces only the 1999 NEC with no exceptions in accordance with the Florida Building Code.