Unit Identification Code
The Unit Identification Code (UIC) is a six character alphanumeric code that uniquely identifies each United States Department of Defense entity. The UIC is often used on various paperwork to assign a soldier to a specific company in which they fall under. The first character is the Service Designator: The next three characters indicate the Parent Unit Designator. These vary from branch to branch and provide information about the type of unit. For example, in the US Army, the parent unit designation breaks down as such: The final two characters indicate the Descriptive Designator. They describe the  specifics characteristics of the unit. For example, the parent Battalion unit for the Army will use "AA." A child Company unit, such as A Company, will use "A0." The UIC is also used by commanding officers to identify their unit to a higher military unit, where the specific information of the unit can easily be researched and information can be accessed. It remains unclear as to the origins of UIC's, but they are assigned to all military units and organizations, as well as federal government organizations.