Treatise on Armament Technology, Volume 71

Military Regulations, Part II (Page 6)

...refrain from destroying civilian houses and warehouses, or felling forests and trees.

Twenty-eighth: When entering foreign territory, no person shall be permitted to enter enemy boundaries to draw and drink water from rivers or wells, for fear that poison has been placed within. original: 賊界 (zeijie); literally "rebel boundaries," referring to territory held by the enemy. Poisoning wells was a common defensive tactic against invading forces.

Twenty-ninth: Upon entering foreign territory, no one shall—without receiving a direct order—arbitrarily dig up water embankments or set fires that spread to destroy stockpiles and gathered resources.

Thirtieth: If a watch post fails to record or relay the nightly signals, or if unauthorized fires are lit while at a lodging, any officers or soldiers who are aware of these actions but collude or tolerate them shall be prosecuted for their crimes. Maintaining "night signals" (夜號 - yehao) was essential for distinguishing friend from foe in the dark.

Thirty-first: If the guarding of the perimeter is not secure, the guilt and punishment shall extend to the commanding officer. 主吏 (zhuli): the primary official or officer in charge of a specific unit or duty.

Thirty-second: Those who refuse to accept their assignments, or commanding officers who are not fair and impartial in the distribution of duties, shall be held accountable for the resulting crimes.

Thirty-third: It is strictly forbidden to bring unauthorized colors, foreign goods, or women into the military camp. original: 異色 (yise); "unusual colors." This likely refers to non-regulation clothing or banners that could disrupt visual signaling or hide an infiltrator’s identity.