bb system means going Dutch. Bb system is the translation of English "algebraic Average", which is the abbreviation of English average, and bb system is a derivative of AA system, which means that each pays for his own consumption.

for example, if you hold a dinner party, there will be 11 people attending, and the food and beverage expenses will be * * * 2,111 yuan, and everyone will have to pay for the food and beverage expenses in 211 yuan. This payment form is the standard bb system. Bb system was popular in foreign countries, and now it is becoming popular in Chinese mainland.