3GPP 24.501 v20.0.0 — the document's own text
8.2.7.12 LADN information
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The network shall include this IE if there are valid LADN service area(s) for the subscribed DNN(s) of the UE in the current registration area.