Dear Doc Jargon,I just saw a term after visiting the local military museum that has me wondering what it means. We were looking at the uniforms from when our Soldiers served in Vietnam and Korea. The sign at the display said. "Soldiers were each issued several sets of O.D. Greens." I was wondering what kind of green "O.D." is. Can you explain it?Sincerely, Mean Green Retired Military Machine SpouseDear Mean Green,I'm happy to explain the term to you. Actually, I'm going to explain a couple of related color terms that have been associated with military uniforms in our history. The first is the OD green you asked about. It stands for olive drab green. That has been the common term since the uniforms were first issued. However, the official term from the military catalog was OG or olive green and it was the color of the utility uniform of all branches of service from 1952 until 1989. The designation of OG-107, and a darker shade, referred to as OG-105, came from the Army's code for the color and material each uniform was made of. The OG-105 was cotton and the OG-107 was a polyester blend. I hope you aren't too mean or too green and that you have a wonderful holiday season.Sincerely, Doc Jargon.Email your military lingo questions to Doctor Jargon at doctorjargon@gmail.com.