XL-200P, so using RPM2.
Set RF power to RF safe. Lowest possible.
In P25 systems data pages,
Set power to low, auto registration to never. Unit registration to never.
Advanced P25 user login set to no login suppported IF relevant. Leave alone if not.
Misc options, uncheck all except TDMA capable if it's a Phase II system.
In sets-p25 groups, uncheck TX, uncheck Calls. For Every group.
Leave system NAC to default/0. Don't need it for RX.
All references to site ID need to carry the correct site number. It's usually the same for all entries of site ID numbers, for any given system.
I haven't found a relevant data inhibit checkbox for P25 system data. Where are you seeing that?