The Great Ming Code ordered that the brokers of cities and villages, 牙行, be chosen from households that held property. Officials gave them seals and registers. Anyone who acted as a broker without a license received sixty strokes, and his fees went to the state.
The Handian dictionary defines 牙行 as a person or firm that helps buyer and seller close a deal and takes a commission. Its example comes from a Ming story: “When great households need someone to stand in the middle and guarantee, they often use him. He is plainly a broker without hair.” The man described is a monk.