Define “shall”
a mandatory requirement
Define “should”
a nonmandatory but preferred method
of accomplishment
Define “may”
an acceptable method of accomplishment
Define “warning”
an essential operating
or maintenance procedure, practice, condition,
statement, etc. which if not strictly observed,
could result in injury to, death of, or long term
health hazards to personnel
Define “caution”
an essential operating
or maintenance procedure, practice, condition,
statement, etc., which if not strictly observed,
could result in damage to or destruction of
equipment, or loss of or degraded mission effectiveness