I'm tryin to add a text comment (not a note) to a pdf file.
I create a date.ps file with contains the text comment :
%! 
/Arial findfont 
30 scalefont 
setfont 
newpath 
10 720 moveto 
(PAID on 5.1.2013) show 
showpage

and I launch the shell command with $i=name of the pdf file to tag:
gs -q -dNOPAUSE -dSAFER -dBATCH -sOutputFile=$RFP/$DOMAINE/$NEWNAME -sDEVICE=pdfwrite -sPAPERSIZE=a4 date.ps $i

This works, but it create a new 1st page empty with the text "PAID on 5.1.2013" alone.

I do not find the trick to overlay the text on the 1st page of the original pdf.

Can you help me pls