On this day 41 years ago, on February 27, 1984 (January 26, 1984 in the lunar calendar), the State Council promulgated the "Legal Units of Measurement of the People's Republic of China". On February 27, 1984, the State Council issued the "Order on Uniform Implementation of Legal Units of Measurement in our country" and promulgated the "Legal Units of Measurement of the People's Republic of China" at the same time. In accordance with the requirements of the State Council, legal units of measurement must be used in books and periodicals published since 1986. The commonly used permitted and non-permitted units stipulated by the state and their conversions are listed in Table 1 for the formation of decimal multiples and fractional units.