What year does the production date u of Hong Kong goods stand for?

When you buy cosmetics in Hong Kong, you can see the batch number and production time. In Hong Kong, U means 1999 is the date of production.

take for example

Like biotherm.

BIOTHERM, usually, it consists of two English words and three numbers. For example, CV 150, the first English letter C represents the place of origin, and the second English letter V represents three digits after the year of manufacture. S =1997t =1998u =1999v = 2000, so CV 150. The shelf life of +050 days is usually three years, that is, until May 2003. In addition, the batch numbers of HR, Lancome and Vichy of Helena Rubinstein are the same as those of biotherm.

Imported products are often different from domestic products, and the shelf life is not directly expressed by the year, month and day, but by the batch number. If you don't have relevant knowledge, you can't understand it at all, which will bring a lot of confusion to buyers. Products of different brands in different countries often have different batch numbers.