"Then the CCN commander arrived in all his magnificence, garbed in a black windbreaker over jungle fatigue pants and shower shoes, his head topped by a green beret. … With practiced flair, Lieutenant Colonel Warren swept aside the top secret curtain, then watched our amazed faces as reality sunk in." - John L. Plaster "Secret Commandos: Behind Enemy Lines with the Elite Warriors of SOG"
Everything about the Studies and Observations Group was a mystery and it didn't exist in any official capacity. If you could find out enough about it to find someone that had been there to vouch for you you had the opportunity to sign up for what essentially was suicidal recon missions into "neutral" countries. In the likely scenario that you were captured or disappeared the government would deny your existence and would make up a more convenient story to tell your family.
The Counterinsurgency Support Office ("CISO") developed and sourced equipment for SOG's use in order to maintain a level of deniability about the cross border operations, including watches, guns, knives, rucksacks, special rations, and uniforms. Nothing that was used was to be traceable back to the U.S. Government. What has become known as the 1-0 jacket by collectors was a black windbreaker that CISO sourced for the SOG troopers for field use. When it was found that the jackets made too much noise in the bush the soldiers repurposed them as team jackets. The jackets were embroidered/decorated with their names, units, qualifications and other personalizations. Later in the war the SOG members would have black windbreakers custom made for each team in Vietnam or in places like Thailand, Taiwan, and Hong Kong.
Against the backdrop of the ugly reality of war and the unique harshness of the Vietnam War in particular, the 'Nam featured, quite paradoxically, some of the most amazing and outlandish custom tailoring. For example the legendary tiger stripe uniform, adopted by American advisors in order to better blend in with the South Vietnamese troops, weren't available in "American sizes" so many of the US troops had to have them custom made in Vietnam. From there a litany of custom/unauthorized unit and morale patches, uniforms, equipment and clothing like the 1-0 jacket were made. As a nod to the custom tailoring of the war the 0-0 jacket features rip-stop woodland/ERDL camo sleeve liners. When the jacket is worn sleeves down it's just any all-black windbreaker. Button snap cuffs were specifically used so that as desired the sleeves can be rolled up showcasing the camo liner. While tiger stripes and OG-107s were the icons of the conflict the new "technology" of the period was ERDL camouflage, which was later adapted after Vietnam into the iconic Woodland camouflage.
1-0 was the designation for the U.S. military contingent's leader and the recon team leader. Each recon team had on average 2-3 U.S. military advisors/leaders. The majority of the recon team was made up of indigenous personnel (Montagnard, Nùng, and Vietnamese). For the indigenous personal the numbers were reversed, with 0-1 the designation for the translator. The "1-0 jacket" is a bit of a misnomer since all the U.S. team members, not just the team lead, were entitled to wear the black windbreakers. Out of respect for those brave men we chose a designation that would not have been used and wryly implies our uninitiated status, hence the 0-0 jacket, because "you weren't there man…."