BCD536HP programming code question

In reading my FD radio I noticed on the P-25 channels they use NAC 293 plus D131N. OK, there is only one spot to put the decode info. I allowed it to do its own and it always came up with NAc293, and never the d131n. But it also allows more traffic that is not from our site to enter. Should I drop the NAC and use the d131n?

Thanks in advance.

Bob

BCD536HP programming code question