Format,Description,Reference
0,Reserved,[RFC3411]
1,IPv4 address,[RFC3411]
2,IPv6 address,[RFC3411]
3,MAC address,[RFC3411]
4,administratively assigned text,[RFC3411]
5,administratively assigned octets,[RFC3411]
6,local engine,[RFC5343]
7-127,Unassigned,
128-255,Enterprise-specific,[RFC3411]