OUTFIL REMOVECC,
HEADER2=(1:C'PAGE HEADER'),
OUTREC=(1,4,5:C'OUTREC FOR DATA')
Both the 'PAGE HEADER' string and the 'OUTREC FOR DATA' string start in position 5 of their respective output records. For HEADER2, you use 1: because 4 must not be added to the output column for the RDW, even though the RDW appears in the header record. For OUTREC, you use 5: because 4 must be added to the output column for the RDW. Just be aware of this difference and specify your output columns accordingly.
When you specify an input field in a HEADERn or TRAILERn parameter, you must add 4 for the RDW to the starting position as you do for a BUILD, OUTREC, OVERLAY, IFTHEN BUILD, IFTHEN OUTREC, IFTHEN OVERLAY or IFTHEN PUSH parameter. However, you cannot specify the variable part of the input record (that is, position without length) in a HEADERn or TRAILERn parameter, as you can for a BUILD, OUTREC, IFTHEN BUILD or IFTHEN OUTREC parameter.