Upload Custom File Types

//Upload Custom File Types
function my_custom_mime_types($mimes)
{
    $mimes['ai'] = 'application/postscript'; //Adobe Illustrator
    $mimes['indd'] = 'application/postscript'; // Adobe InDesign
    $mimes['ofm'] = 'application/postscript'; // Embroidery
    $mimes['dst'] = 'application/postscript'; // Embroidery
    return $mimes;
}
add_filter('upload_mimes', 'my_custom_mime_types');