An exchange is a type of retail store found on United States military installations worldwide. Originally akin to trading posts, they now resemble contemporary department stores or strip malls. Exact terminology varies by armed service; some examples include base exchange (BX), and post exchange (PX), and there are more specific terms for subtypes of exchange. Operations Base exchanges sell consumer goods and services to authorized patrons such as active duty, reserve, national guard, retired members of the U.S. Uniformed Services and their dependents. Other authorized patrons include honorably discharged veterans certified 100% disabled and/or totally and permanently disabled (TPD) by the Veterans Administration, recipients of the Medal of Honor, military transition personnel , DoD employees when stationed outside the United States, Red Cross personnel who are U.S. citizens assigned outside the United States with the military service. Authority to use these facilities is normally determined by presentation of the U.S. Uniformed Services Privilege and Identification Card, either when entering the store or when paying for goods and services. Online base exchange shopping privileges were extended to all honorably discharged veterans beginning on November 11, 2017. The DEERS database is used to verify non-disabled veterans' eligibility for the online shopping benefit. Limited base exchange privileges are extended to members of the Civil Air Patrol and United States Coast Guard Auxiliary. Reserve Officer Training Corps (ROTC), Junior Reserve Officer Training Corps (JROTC), United States Naval Sea Cadet Corps, and Civil Air Patrol cadets may all have varying degrees of privileges (such as only being allowed to shop for uniform items or only being allowed when visiting installations as part of a sponsored activity). Foreign national active duty officer and enlisted members, when visiting U.S. military installation for unofficial business. Merchandise is restricted to quantities required for personal use. At many overseas locations, exchange privileges are determined as part of the local Status of Forces Agreement. Shopping privileges are also generally extended in overseas locations to U.S. federal government civilian employees and their dependents who are assigned overseas. Shopping privileges can vary overseas according to applicable status-of-forces agreements with host nations. A typical exchange is similar to a department store, but other services such as military clothing sales/uniform shops, barber shops, hair care, beauty, laundry/dry cleaning, gas stations, fast food outlets, convenience stores ("Expresses"), beer and wine sales, liquor stores ("Class Six" or "Package Stores"), lawn and garden shops, movie theaters and even