(PHP 4, PHP 5 < 5.3.0, PECL fdf SVN)
fdf_set_ap — Set the appearance of a field
$fdf_document,$field_name,$face,$filename,$page_numberSets the appearance of a field (i.e. the value of the /AP key).
fdf_documentfield_namefaceFDFNormalAP, FDFRolloverAP and FDFDownAP.filenamepage_number