Type,Name,Reference
0x00,Reserved,[RFC9508]
0x01,T_ECHO_RETURN_FORWARDER,"[RFC9508, Section 4.2]"
0x02,T_ECHO_RETURN_APPLICATION,"[RFC9508, Section 4.2]"
0x03,T_ECHO_RETURN_OBJECT,"[RFC9508, Section 4.2]"
0x04-0xFF,Unassigned,