WordPress at a glance
action is not described

delete_postmeta action-hook . WP 2.9.0

Fires immediately before deleting metadata for a post.

Usage

add_action( 'delete_postmeta', 'action_function_name_7865' );
function action_function_name_7865( $meta_ids ){
	// action...
}
$meta_ids(array)
An array of post metadata entry IDs to delete.

Where the hook is called

delete_metadata()
wp-includes/meta.php 402
do_action( 'delete_postmeta', $meta_ids );

Where the hook is used (in WP core)

Does not used.