string
Specifies the FAO control string to be used in generating a
prefix to a verified command line. The following rules apply:
o No more than 64 characters are allowed in the control string.
o The resulting string can be no longer than 64 characters.
o Basic formatting FAO directives can be used ("!/", "!_", "!^",
"!!", "!%F", and "!n*c").
o Time and date FAO directives can be used ("!%T" and "!%D").
o Repeat counts can be used ("!n(DD)").
o Output field length specifications can be used ("!lengthDD").
o Combination of repeat count and output field length can be
used ("!n(lengthDD)").
o FAO directives that require arguments will always receive a
value of zero.