Wubei Zhi (Vol. 47)

Raising a Red Flag indicates a need for whetstones, timber, firewood, or reeds. Raising a Yellow Flag indicates a need for sand, stones, bricks, or tiles. Raising a White Flag indicates a need for water, boiling liquids, or "foul materials" original: "不潔之物" (bujie zhi wu). In siege warfare, this refers to the use of nightsoil or animal carcasses, often boiled and poured onto attackers to cause infection and chemical burns.. Raising a Black Flag indicates a need for leather, felt, hemp rope, brass, iron, shovels, cauldrons, axes, or chisels.

Raising the Double Rabbit Flag Double Rabbit Flag (Shuangtu Qi): A specific signal flag used to call for high-priority reinforcements. indicates a need for elite warriors and sharp-witted soldiers. Raising the Bear and Tiger Flag Bear and Tiger Flag (Xionghu Qi): A signal for heavy weaponry units. indicates a need for halberds, spears, bows, arrows, knives, and swords.

The Alarm Flag Alarm Flag (Jing Qi): A general distress signal. alerts the officer in charge to look for the accompanying colored flag and supply the necessary materials accordingly. Within the city, all elderly men, youths, and women—except for those assigned to cook for the garrison—must be pressed into service on the walls. They are to be divided into eight teams. Those who are literate must be appointed to inspect and manage the regular flags and the coordination of these eight divisions.

Maozi Maozi is the respectful name for Mao Yuanyi (1594–1641), the compiler of this treatise. says:

The methods recorded above are the ancient ways. In more recent times, there have been various insights into city defense found in works such as the Records of City Defense, the New Treatise on Military Efficiency Ji Xiao Xin Shu: The famous military manual by General Qi Jiguang (1528–1588), emphasizing practical training and squad tactics., the Chapter on Guarding Posts, and the Records of Practical Administration. There is also the Illustrated Compendium on Maritime Strategy Chou Hai Tu Bian: A 1562 geographical and military work focused on defending the Chinese coast against "Wokou" pirates., which contains the debates and theories of over a hundred scholars of that era. Figures such as Tang Airu, Luo Gongchen, and Tang Shu—dozens of such men—have delved deeply into these matters The original text uses "皆鑿" (jie zao), literally "all have chiseled/bored into," suggesting these authors provided penetrating or highly detailed analysis..