VTOF is only available on OUTFIL, so cannot be in IFTHEN anyway, as IFTHEN is available for INREC and OUTREC.
SORT FIELDS=COPY
OUTFIL VTOF,
IFTHEN=(WHEN=INIT,
BUILD=(1:7,10,21:7,2,23:10,2,25:13,4,31:10X,51:C'X')),
IFTHEN=(WHEN=INIT,
OVERLAY=(31:21,8,Y4W,ADDDAYS,+10,TOGREG=Y4T))
OUTFIL VTOF,
IFTHEN=(WHEN=INIT,
BUILD=(1:7,10,21:7,2,23:10,2,25:13,4,31:10X,51:C'X')),
IFTHEN=(WHEN=INIT,
OVERLAY=(31:21,8,Y4W,ADDDAYS,+10,TOGREG=Y4T))
