1st means IOC 1st Information Operations Command Land in Military
Similar to 1st
100BASE-T - 100 Megabits per second, Baseband, Twisted pair100ID - 100th Infantry Division
101AD - 101st Airborne Division
102 RQS - 102nd Rescue Squadron
106 RQW - 106th Rescue Wing
10BASE-T - 10 Megabits per second, Baseband, Twisted pair
11AD - 11th Airborne Division
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