The cpdf_add_annotation() adds a note with the lower left corner at (llx, lly) and the upper right corner at (urx, ury). Geeft TRUE terug bij succes, FALSE indien er een fout is opgetreden.
The optional parameter mode determines the unit length. If it is 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.