3GPP 24.501 v20.0.0 — the document's own text
8.3.1.11 DS-TT Ethernet port MAC address
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 in the message if the UE supports transfer of port management information containers and the UE requests to establish a new PDU session of "Ethernet" PDU session type.