The culture of flying flags dates again centuries, serving as a way of communication on battlefields

https://golf-wiki.win/index.php/Proudly_Displaying_the_Thin_Red_Line:_A_Nod_to_Our_Brave_Firefighters

The lifestyle of flying flags dates back centuries, serving as a way of verbal exchange on battlefields. They conveyed messages of allegiance and victory, allowing armies to coordinate events and concepts with no verbal communication.