battle standard
A flag or banner carried by soldiers into battle to show their allegiance. If the fabric is horizontal, it's a war flag; otherwise, if it's vertical, it's a a war banner.
If the flag is being used in a military context but is not being carried by infantry or cavalry (such as on warships), simply tag the relevant country's flag.
See also
The following tags implicate this tag: war_banner and war_flag (learn more).
