3GPP 24.501 v20.0.0 — the document's own text
8.2.19.14 Network slicing indication
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
This IE shall be included if the user's network slicing subscription has changed in the UDM of a PLMN or an SNPN.