InputFile can be the name of an unencrypted PDF file - it may *not* be the name of the output file.
InputFileMode can be:
pwIgnoreInput - do nothing
pwAppendToInput- copy input to output and append new data
wpConvertInputToWatermark - copy input to output but convert pages to PDF XForms which then can be used as watermarks :UseWatermark( 'inpage' + IntToStr(number))
wpUseInputAsWatermark - like wpConvertInputToWatermark but use the watermarks
Unfortunately are the watermarks not so reliable for display.