4 Charlie (Earth-2042)

4 Charlie was a Systems Alliance Army unit stationed on Reach during the Clone Wars. During the Fall of Reach, they fought in the Siege of New Harmony, where 4 Charlie 27 and his team were sent to disable a CIS communications jammer in Club Errera in the Vyrant Telecom Tower. They soon became pinned down by a group of Mgalekgolo, but SPARTAN-B312 was able to assist them and destroy the jammer.

Source

 * https://www.halopedia.org/4_Charlie