Bill,
The example that I am most familiar with is the rule that says you can't use a single screw to support a receptacle. I made the original proposal (18-51 for the '90 code) on that subject and it was accepted by all of the panel members in the ROP(TCR), (comments 18-26 through 18-31) but rejected by all in the ROC(TCD). There have been many others over the years. Just look at any of the code changes books that are published early. These early publications are written based on the ROP and there are always things that change in the ROC and even at the May meeting.
I'm hoping that the ROC will accept my proposed change on the term equipment grounding conductor. CMP 5 accepted my proposal, but was one vote short of the required 2/3s majority. Comments on this proposal may result in a change. We all have a voice in the code writting process and if you don't like what you see in the ROP, you should submitt a comment.
Don
