Membership in the Order shall be limited to men and women 18 years of age and older (see (d) below) as follows: (a) All United States military veterans and other non-military personnel serving in the Vietnam War Theater of Military Operations between 1 July 1958-28 March 1973 and 29-30 April 1975. The Vietnam War Theater of Operations is defined as service in the geographical theater areas of Vietnam, Thailand, Laos, or Cambodia from 1 July 1958 through 28 March 1973 and the evacuation of Saigon (USN, USMC, and USAF) from 29-30 April 1975. (b) Lineal descendants of (a). (c) Collateral descendants (to first-cousins ONLY) of (a). (d) Junior members between the ages of 10-18 years, either lineal or collateral of (a).