Code,Sub-Option Description,Reference
1,Agent Circuit ID Sub-option,[RFC3046]
2,Agent Remote ID Sub-option,[RFC3046]
3,"Sub-option 3 is reserved and should      
not be assigned at this time;
proprietary and incompatible usages
of this sub-option value have been
seen limited deployment.",[Ralph_Droms]
4,DOCSIS Device Class Suboption,[RFC3256]
5,Link selection Sub-option,[RFC3527]
6,Subscriber-ID Suboption,[RFC3993]
7,RADIUS Attributes Sub-option,[RFC4014]
8,Authentication Suboption,[RFC4030]
9,Vendor-Specific Information Suboption,[RFC4243]
10,Relay Agent Flags,[RFC5010]
11,Server Identifier Override Suboption,[RFC5107]
12,Relay Agent Identifier Sub-option,[RFC6925]
13,Access-Technology-Type Sub-option,[RFC7839]
14,Access-Network-Name Sub-option,[RFC7839]
15,Access-Point-Name Sub-option,[RFC7839]
16,Access-Point-BSSID Sub-option,[RFC7839]
17,Operator-Identifier Sub-option,[RFC7839]
18,Operator-Realm Sub-option,[RFC7839]
19,DHCPv4 Relay Source Port Sub-Option,[RFC8357]
20-150,Unassigned,
151,DHCPv4 Virtual Subnet Selection Sub-Option,[RFC6607]
152,DHCPv4 Virtual Subnet Selection Control Sub-Option,[RFC6607]