Analysis of information sources in references of the Wikipedia article "Joe L. Hayes Jr." in English language version.
19 OCTOBER 1967 - Airman grades, titles, and terms of address were revised.to make the following changes, and to restore NCO status to grade E-4: Airman Basic (no stripes), Airman (one stripe), Airman First Class (two stripes), Sergeant (three stripes), Staff Sergeant through Chief Master Sergeant, and First Sergeants, no change.
