3GPP 38.300 v19.3.0 — the document's own text
4.6 Radio Access Network Sharing
Taught in 4. What NR is — the shape of the 5G radio network (TSG RAN — the group that specifies the radio, in depth), 4. What NR actually is, in the shape its own document gives it (TSG RAN — the group that specifies the radio, overview), 3. What NR is, read off the document itself (TSG RAN — the group that specifies the radio, quick start).
NG-RAN supports radio access network sharing as defined in TS 23.501 [3].
If NR access is shared, system information broadcast in a shared cell indicates a TAC and a Cell Identity for each subset of PLMNs, PNI-NPNs and SNPNs. NR access provides only one TAC and one Cell Identity per cell per PLMN, SNPN or PNI-NPN. In this version of the specification, a Cell Identity can only belong to one network type among PLMN, PNI-NPN or SNPN as defined in TS 23.501 [3].
Each Cell Identity associated with a subset of PLMNs, SNPNs or PNI-NPNs identifies its serving NG-RAN node.