What does it mean that the bottle cap of Tsingtao beer says A?

A is the abbreviation of Asahi Beer Co., Ltd., which was founded in 1889 and is one of the most famous beer manufacturers in Japan.

1999, Asahi Beer Co., Ltd., Itochu Corporation, Japan Gold Products and Tsingtao Brewery Co., Ltd. jointly built Shenzhen Tsingtao Brewery Asahi Co., Ltd., with a total investment of 52.37 million US dollars.