The Nobori (幟) is a long, narrow, and vertical banner that was commonly used during the Sengoku period in Japan as a form of military communication to denote sub-units of an army or simply to provide a large heraldic display with dozens of identical flags.
Usage of Nobori
Today, the Nobori is used during festivals and sporting events, typically Japanese ones (in sports they take the place of the common flags and signs among the Western public), advertisements, and even to identify political parties during an electoral campaign.