Treatise on Armament Technology, Volume 101

Military Equipment: Warfare — Banners and Flags, Part 3

The Squad Leader’s identifying flag is one square foot in size. The pole used for this flag is a long spear, fifteen feet in length. The flag itself is to be suspended at a height of nine feet from the ground.
original: 隊長認旗方一尺桿用長鎗一丈五尺旗懸高九尺. In the Ming military system popularized by General Qi Jiguang, the "long spear" served as both a primary weapon and a mobile flagpole, ensuring the squad leader could lead the charge while remaining a visible point of alignment for his twelve men.

The total weight is two catties.
original: 重二斤 (zhòng èr jīn). A "catty" or jin during the Ming period was approximately 590 grams, making the entire assembly roughly 1.2 kilograms or 2.6 pounds.

Squad Leaderoriginal: 隊長 (duìzhǎng). The leader of a duì, the smallest tactical unit. In the "Mandarin Duck Formation," this leader stood at the front, directing the combined efforts of spearmen, shield-bearers, and branch-wielders.

Identifying Flagoriginal: 認旗 (rènqí). Also known as "recognition flags," these allowed soldiers to identify their specific unit and leader amidst the smoke and chaos of the battlefield.

Measurements (Zhang and Chi)original: 丈 (zhàng) and 尺 (chǐ). One zhàng contains ten chǐ. In the 16th century, 15 chǐ (one zhàng five chǐ) would be roughly 4.8 meters or 15.7 feet.