Value,Description,Reference
0-15,Reserved. Never to be made available for allocation.,[RFC7274]
16,Metadata Label Indicator (MLI),[RFC8595]
17,Metadata Present Indicator (MPI),[RFC8595]
18,Flow-ID Label Indicator (FLI),[RFC9714]
19-239,Unassigned,
240-255,Reserved for Experimental Use,[RFC7274]
256-1048575,Reserved. Not to be made available for allocation without a new Standards Track RFC to define an allocation policy.,[RFC7274]