void pdf_set_info_subject(info info, string subject);
The PDF_set_info_subject() function sets the subject of a pdf document. It has to be called after PDF_get_info() and before PDF_open(). Calling it after PDF_open() will have no effect on the document.
Note: This function is not part of the pdf library.
Note: This function takes a different first parameter if pdflib 2.0 support is activated. The first parameter has to be the identifier of the pdf document as returned by pdf_open(). Consequently, pdf_open() has to be called before this function.