WordPress at a glance
filter is not described

parent_post_rel_link filter-hook . WP 1.0

Usage

add_filter( 'parent_post_rel_link', 'filter_function_name_7825' );
function filter_function_name_7825( $link ){
	// filter...

	return $link;
}
$link
-

Where the hook is called

get_parent_post_rel_link()
parent_post_rel_link
wp-includes/deprecated.php 2768
return apply_filters( "parent_post_rel_link", $link );

Where in WP core the hook is used

Usage not found!