I was reading some pages in Web and this line is what I know the syntaxis. It's not in the man page or anywhere else.
For example from man:
steve CSNETS = (operator) /usr/local/op_commands/
The user steve may run any command in the directory /usr/local/op_commands/ but only as user operator.
1 2 = (3) 4 is a syntaxis here.
"The user steve may run any command ... only as user operator"
I don't get it. Who is allowed to run any command - user steve or user operator?