"more" and "less" are more or less the same as
"pg" - an alias is obvious - but then it is not
exactly the same with the same functionality??
"truss" used on solaris boxes.
as per Sun.
"The truss (trace system calls and signals) command displays useful process-related information:
System calls performed, their arguments and return values
Signals received by the process
Machine faults incurred by the process"
So unless one have worked on a sun box - it is possible that the command will be unknown.