The PDF_set_info() function sets an information field of a pdf document. Possible values for the fieldname are 'Subject', 'Title', 'Creator', 'Author', 'Keywords' and one user-defined name. It can be called before beginning a page.
Nota: This function replaces PDF_set_info_keywords(), PDF_set_info_title(), PDF_set_info_subject(), PDF_set_info_creator(), PDF_set_info_sybject().