The tradition of flying flags dates back centuries, serving as a way of verbal exchange on battlefields

https://dantesbyk985.birchreport.com/posts/protecting-students-or-policing-patriotism-the-us-flag-at-school

The way of life of flying flags dates again centuries, serving as a means of communication on battlefields. They conveyed messages of allegiance and victory, permitting armies to coordinate activities and suggestions with out verbal communication.