private function addMetaItemRef( \Aimeos\MShop\Common\Item\ListRef\Iface $item, array &$expires, array &$tags, $tagAll )
	{
		foreach( $item->getListItems() as $listitem )
		{
			if( ( $refItem = $listitem->getRefItem() ) === null ) {
				continue;
			}

			if( $tagAll === true ) {
				$tags[] = str_replace( '/', '_', $listitem->getDomain() ) . '-' . $listitem->getRefId();
			}

			if( ( $date = $listitem->getDateEnd() ) !== null ) {
				$expires[] = $date;
			}

			$this->addMetaItemSingle( $refItem, $expires, $tags, $tagAll );
		}
	}