Okla. Stat. tit. 72 § 224
The words "war veterans", used in the foregoing sections shall be construed to mean such ex-service persons as were discharged under other than dishonorable conditions, and who (a) served in any branch of the military or naval service of the United States during the period of any war, campaign, expedition, in which the United States participated, including but not limited to those who (b) served in the military or naval forces of the United States at any time during the period from April 6, 1917, to November 11, 1918, both dates inclusive, or who (c) served in the military or naval forces of the United States at any time during the period of December 7, 1941, and September 2, 1945, both dates inclusive, or who (d) served in the military or naval forces of the United States on or after June 25, 1950, during the period of time in which the United States participates in a war, military or naval campaign, or expedition.
Okla. Stat. tit. 72, § 224