3GPP 24.501 v20.0.0 — the document's own text
8.2.26.4 non-IMEISV PEI
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The 5G-RG or the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) shall include this information element, if the IMEISV was requested within the corresponding SECURITY MODE COMMAND message, the IMEISV is not available but MAC address is available.
The UE shall include this information element, if the IMEISV was requested within the corresponding SECURITY MODE COMMAND message, the IMEISV is not available but EUI-64 is available.