What is "matoi"

A was a flag used in Edo period Japan by to notify people of a fire near or within a building. It was taken up on a roof near the burning building by the and waved to draw the attention of other groups of firefighters, who would then hurry to the site of the fire to assist. Each different group of firemen in the Edo period had their own matoi to identify themselves. In modern Japan, the matoi is only used for ceremonial purposes.