3GPP 24.501 v20.0.0 — the document's own text
8.2.6.17 LADN indication
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The UE shall include this information element when the UE needs to request LADN information for specific LADN DNN(s) or to indicate a request for LADN information.