Value,Description,Reference
1,Routing Information,"[Xerox System Integration Standard: Internet Transport 
Protocols. XSIS 028112, December 1981.]"
2,Echo,"[Xerox System Integration Standard: Internet Transport 
Protocols. XSIS 028112, December 1981.]"
3,Router Error,"[Xerox System Integration Standard: Internet Transport 
Protocols. XSIS 028112, December 1981.]"
5,Courier,"[Xerox System Integration Standard: Courier: The Remote
Procedure Call Protocol.  XNSS 038112, December 1981.]"
8,Time Protocol,"[Xerox System Integration Standard: Time Protocol.  XNSS
088404, April 1984.]"
40-77,Experimental,