Clone trooper sergeants wore Phase I clone trooper armor with olive green markings on their helmets and torso at the beginning of the Clone Wars. Some clone trooper sergeants didn't have green flashes on their battle armor. Such troopers included the sergeant aiding in Anakin Skywalker's search for Asajj Ventress on Yavin 4 after the Battle of Muunilinst, as well as two unmarked clone sergeants participating in the Battle of the Rishi moon and in the Battle of Ryloth.
As one of the non-commissioned officer ranks in the Grand Army, clone sergeants were in the thick of battle along with the troops under their command. They commanded squads of nine clone troopers. Clone lieutenants coordinated the squads under the sergeants' command into platoons.
The rank of sergeant was also applied to ARC troopers as a ranking of unknown command placement. These ARC sergeants also bore green markings. The most notable of these sergeants was Null-class Advanced Recon Commando Null-12, nicknamed A'den. Another ARC sergeant operated with Anakin Skywalker during the Battle of Praesitlyn, during an attempt to free hostages.
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