“840” tags are tags that have undergone review and approval by USDA-APHIS to meet several quality, safety, and retention standards. “840” is the first of 15 digits and indicates that the animal was born in the United States.
“840” tags may have an additional component allowing the number to be read electronically (i.e.- an RFID tag) but are also required to be visually readable from at least 30 inches. The orange tags used for brucellosis vaccinates and the silver metal NUES tags are also approved for official identification by USDA APHIS. They are visual only tags without specific readability requirements and may be used in non-U.S. origin cattle and bison.