3GPP 24.501 v20.0.0 — the document's own text
8.2.24.2 PDU session status
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
This information element shall be included when the UE needs to indicate over non-3GPP access the PDU sessions that are associated with the 3GPP access type that are active within the UE.