Raws li qhov tshwj xeeb ntawm lub qhov rooj hluav taws, txhua lub qhov rooj hluav taws muaj nws tus kheej daim ntawv lo, uas yog daim npav ID hluav taws xob ntawm lub qhov rooj hluav taws. Feem ntau hais lus, hluav taws qhov rooj manufacturers yuav tsum affix daim ntawv lo ntawm txhua lub qhov rooj kiag li thaum cov khoom tawm hauv lub hoobkas.