These are the base MiG code numbers for each subsystem in the GNU Hurd.
Each subsystem takes 200 in space.  

FS		20000	Filesystem nodes
IO		21000	Generic IO
FSYS		22000	Filesystem control operations
MSG		23000	Calls made on process message ports
PROCESS		24000	Process abstraction
AUTH   		25000	Authentication
SOCKET 		26000	Sockets
NEWTERM		27000	Creation of terminal processing thingies
TERM		28000	Terminal-specific operations
STARTUP		29000	System initialization and destruction
EXEC		30000	Process execution
BOOT		31000	Bootstrapping
CORE		32000	Core dumping
INTR		33000	Interruption
IFSOCK		34000	S_IFSOCK node protocol for AF_LOCAL rendezvous
TAPE		35000	Special control operations for magtapes
TIOCTL	       156000	Ioctl class 't'