Neither mpe(4) nor faith(4) are presently hooked up to /src/sys/conf/GENERIC build so this might be a bit early. mpe(4) has been documented in ifconfig(8) already, but there's no mention of faith(4) in there.
Index: ifconfig.8 =================================================================== RCS file: /cvs/src/sbin/ifconfig/ifconfig.8,v retrieving revision 1.199 diff -N -u -p ifconfig.8 --- ifconfig.8 12 Apr 2010 01:26:29 -0000 1.199 +++ ifconfig.8 6 May 2010 22:33:24 -0000 @@ -171,6 +171,7 @@ At least the following devices can be created on deman .Pp .Xr bridge 4 , .Xr carp 4 , +.Xr faith 4 , .Xr gif 4 , .Xr gre 4 , .Xr lo 4 ,
