Value,Description,Reference
0,Reserved,[RFC9503]
1,Return Path Control Code,[RFC9503]
2,Return IPv4 or IPv6 Address,[RFC9503]
3,SR-MPLS Label Stack of the Return Path,[RFC9503]
4,SRv6 Segment List of the Return Path,[RFC9503]
5-239,Unassigned,
240-251,Reserved for Experimental Use,[RFC9503]
252-254,Reserved for Private Use,[RFC9503]
255,Reserved,[RFC9503]