A unique 15-digit identification number is stored and printed on each single-use, tamper-proof, half-duplex (HDX) label. The farm premises identification number is assigned to a series of tag numbers to be sent and the information is stored in the NAIS database. Each label can be visually verified by viewing the ID number of the printed label or automatically verified with a reader. HDX tags are the best choice when tags will be read with a sidewalk reader or in a packing facility as they have a greater read distance.