/**
 * Callback function for the 'webmention_supported_delete_codes' filter.
 *
 * @param array $string_list 
 * @return array The filtered value.
 */
function my_webmention_supported_delete_codes_callback( array $string_list ) {
    // Your code here.
    return $string_list;
}
add_filter( 'webmention_supported_delete_codes', 'my_webmention_supported_delete_codes_callback' );

apply_filters(
			'webmention_supported_delete_codes',
			array(
				'resource_not_found',
				'resource_deleted',
				'resource_removed',
			)
		)