Kind of dropped, yeah…
Each cell can broadcast a list of permitted NCC to the MS. I’m not sure exactly how it works (or what it does to the MS), but you can check 3GPP 04.18 (NCC Permitted, or PLMN Permitted)
I think it’s very “soft”, it might do something like this:
If the cell broadcast “all” NCC permitted, the MS will decode BCCH/BSIC that contains any NCC.