Flags have been in certain cases used as rallying issues throughout battles; infantrymen could assemble around their colors for morale

https://kylerxkon931.northvaledigest.com/posts/flags-as-historical-artifacts-insights-into-the-civil-war-era-2

Flags have been usually used as rallying elements all over battles; infantrymen could assemble around their shades for morale aid when confronted with overwhelming odds.