《墨子·70章 号令》
城门设主管官员，负责城门和里巷的门，开锁和上锁都必须有守城主将所给的凭证。
门有吏，主者门里，筦闭，必须太守之节。
The city gate should have an official in charge of both the city gate and the doors of the alleys. All the unlocking and locking must be done with the credentials given by the garrison commander.