Location identification (LID) number. A nationally unique number issued by a State, Tribal, and/or Federal animal health authority to a location as determined by the State or Tribe in which it is issued. The LID number may be used in conjunction with a producer's own unique livestock production numbering system to provide a nationally unique and herd-unique identification number for an animal. It may also be used as a component of a group/lot identification number (GIN).
9 CFR § 77.2
As used in this part, the following terms shall have the meanings set forth in this section except as otherwise specified.