3GPP 24.501 v20.0.0 — the document's own text
8.2.25.2 IMEISV request
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The AMF may include this information element to request the UE to send its IMEISV with the corresponding SECURITY MODE COMPLETE message.