S-1 means Army Adjutant/Personnel Staff at the Battalion/Brigade level in Military
Similar to S-1
201MIB - 201st Military Intelligence Battalion20SCVI - 20th South Carolina Volunteer Infantry Regiment
21CLW - 21st Century Land Warrior
21CLWTLD - 21st Century Land Warrior Top Level Demonstration
24 MEU - 24th Marine Expeditionary Unit
24NAF - 24th Numbered Air Force
26PEMR - 26th Pennsylvania Emergency Militia Regiment
View all in Military