Rewrite API

// This is called before flush_rewrite_rules() when the plugin is activatedfunction my_rewrite_rules() {	$archivepage = get_page_by_path( '/race-archives/' );	$archive_handler_url = sprintf( 'index.php?p=%d&', $archivepage->ID );	add_rewrite_rule( 'race-archives/([^/]*)/$', $archive_handler_url . 'raceyear=$matches[1]', 'top' );}//This is called on init.function my_rewrite_tags() {	add_rewrite_tag( '%raceyear%', '([^&]+)' );}