Fetching details from the dictionary...

flag
pataka (banner)
banner (administrative division of Inner Mongolia)
「旌」 has another reading with different meanings.
城の上に旌がはためいているのが見えた。
I could see a flag fluttering above the castle.
祭りの行列では色鮮やかな旌が並んだ。
Colorful flags lined the festival procession.
戦場で旌を掲げて味方を鼓舞した。
They raised the flag on the battlefield to inspire their allies.