/VFC_HEADER={ IGNORE | DATA | KEEP }
Specifies how to handle files in variable-with-fixed-control-area
format (such as batch .log files). By default, the control area is
ignored. /VFC_HEADER=DATA causes the control area, which is normally
hidden, to be treated as part of the normal record contents. A value
of KEEP causes the output file to have the same format as the input
file (rather, as the *first* input file if there is more than one).
If the [first] input file is not in VFC format, /VFC_HEADER=KEEP has
no effect.