The ancient poetry containing the word flag is a couplet poem.

Half a roll of red flag is raining, and the frost is heavy and cold.

Batavia on Yanmenguan Line

Li he

Enemy soldiers rolled in like dark clouds in an attempt to tear down the city wall; Our army was ready, and the sun shone on the armor, glittering with gold.

In autumn, the loud bugle sounded; The soldier's blood became dark in the night.

The red flag rolled half, and the reinforcements rushed to Xiao; The night frost is heavy and the drums are gloomy.

I want to report to you on the golden platform, and I want to take Yulong to your death.