do_action( 'pre_trackback_post', int $post_id, string $trackback_url, string $charset, string $title, string $excerpt, string $blog_name )

112	 * @param string $trackback_url Trackback URL.113	 * @param string $charset       Character set.114	 * @param string $title         Trackback title.115	 * @param string $excerpt       Trackback excerpt.116	 * @param string $blog_name     Site name.117	 */118	do_action( 'pre_trackback_post', $post_id, $trackback_url, $charset, $title, $excerpt, $blog_name );119 120	header( 'Content-Type: text/xml; charset=' . get_option( 'blog_charset' ) );121 122	if ( ! pings_open( $post_id ) ) {123		trackback_response( 1, __( 'Sorry, trackbacks are closed for this item.' ) );124	}