<P> The card is used to control access to military bases, Base exchange (such as AAFES, Navy Exchange, Marine Corps Exchange, Coast Guard Exchange), commissaries and Morale Welfare and Recreation (MWR) facilities . It also serves as proof of eligibility for medical care delivered either directly within the military health system or outside via TRICARE . </P> <P> The modern identification card is called a Common Access Card (CAC) because it is also a smart card that is used with specialized card readers for automatic building access control systems, communications encryption, and computer access . The Common Access Card is now used by members of Active Duty, Reserves, and the National Guard </P> <P> The primary types of U.S. military ID cards being issued today are the CAC for active duty and Reserve members, the Department of Defense (DD) Form 2 for retirees, DD Form 1173 for 100% disabled veterans and DD Form 1173 - 1 for dependents . Until the CAC was phased in starting in late 2003, the DD Form 2 in branch - specific variants served as active duty members' ID . Prior to the October 1993 revision, the DD Form 2 form number was appended with one of five variant codes denoting branch of service (A, AF, N, MC, or CG), and the typewriter - filled blank form variants were overprinted with branch names and logos . Current DD Forms 2 and 1173 are identical for all branches; the DEERS ID workstation prints branch - unique names and logos onto the blank form along with the holder's personal information at the time of issue . Current DD Forms 2 and 1173 variants differ only in the color in which the blank form is printed, indicating the holder's status . DD Forms 2 and 1173 are easily confused as they are similar in appearance and purpose, however they are two distinct forms . </P> <P> The DD Form 2 and 1173 ID \ S cards are color - coded to denote the status of the holder . Possible colors are: </P>

Who is the issuing authority of a military id