3GPP 24.501 v20.0.0 — the document's own text
7.2.2 Message too long
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The maximum size of a NAS message for NR connected to 5GCN is specified in 3GPP TS 38.323 [29].
The maximum size of a NAS message for E-UTRA connected to 5GCN is specified 3GPP TS 36.323 [25].
The maximum size of a NAS message for non-3GPP access connected to 5GCN is specified in 3GPP TS 24.502 [18]