AA制, AB制, and AO制

Remember the AA post previously?

Apparently it's also used in China to mean going Dutch. They call it "AA制" or "AA treat", where "AA" means "Algebraic Average".

From this comes another one: "AB制", or "AB treat".

This has become a fad among young people, where males would choose to pay a bigger slice of the bill, and the remainder would be paid by the females dining with them.

What about the male paying all for the female?

Yup, that would be the "AO制". The "O" here stands for zero, because the female basically paid zero cents.