Kazu no Fuchō

Kazu no Fuchō refers to a numerical code system used in trade and professional settings to conceal prices, quantities, or other relevant information. These specialized codes are a form of occupational jargon (符牒, fuchō) understood only within particular groups or professions. They were originally developed to hide confidential information from customers or outsiders and thus protect internal communication.

In the past, merchants used such numerical codes to communicate purchase prices or the quality of goods among themselves without customers being able to understand that information.

These numerical codes are an important part of traditional commercial practices in Japan. They allow for discreet communication and help improve efficiency while protecting trade secrets. Similar systems can still be found today in certain trading and auction environments.