"21st United States Infantry Regiment" . "5th Battalion, 21st Infantry" . "Battle Cry; \\\"Bore Brother Bore!\\\"" . "21st" . . . "21st Infantry" . . . . . . . "US Army, 21st Infantry" . . "3rd Battalion, 21st Infantry" . "21st Regiment" . . "File:21 INF DUI.png" . . "4th Battalion, 21st Infantry Regiment" . . "21st Infantry Regiment (United States)" . "21st Infantry Battalion" . . . . "23rd Infantry Regiment" . . . "21st Infantry Brigade" . . "21st infantry" . "5th Battalion, 21st Infantry Regiment" . . . . . . . "21st Infantry Regiment" . . . . . . . . . "3rd Battalion, 21st Infantry Regiment" . . . . . . "Gimlet" . "2-21 IN" . . . . "21st Regimental Combat Team" . . . "1861" . . . . . . . "21st U.S. Infantry" . . . . "21st Infantry Regiment (United States)" . . . . . . . . . . . "4th Battalion, 21st Infantry" . . . "3rd Battle Group, 21st Infantry" . . . . . "1st Battalion, 21st Infantry" . . . "Duty" . . .