Lub taub hau luam ntawv yog ib qho meej thiab kim ntawm lub tshuab luam ntawv barcode, thiab nws kuj yog ib qho khoom tawg yooj yim thiab puas yooj yim. Nws yog ib qho khoom siv zoo li lub tsheb thiab nws yuav raug puas tsuaj. Tsuas yog los ntawm kev saib xyuas tas li rau kev saib xyuas tuaj yeem txuas ntxiv lub neej ntawm lub taub hau luam ntawv.