Guidon (United States)

19th century guidon used by the 7th Cavalry Regiment

In the United States Armed Forces, a guidon is a military standard or flag that company/battery/troop or platoon-sized detachments carry to signify their unit designation and branch/corps affiliation or the title of the individual who carries it. A basic guidon can be rectangular, but sometimes has a triangular portion removed from the fly (known as "swallow-tailed").