The directives gave a derogation from using SI units in areas where other units of measure had either been agreed by international treaty, or were in universal use in worldwide trade. They also permitted the use of ''supplementary indicators'' alongside, but not in place of the units catalogued in the directive. In its original form, Directive 80/181/EEC had a cut-off date for the use of such indicators, but with each amendment this date was moved until, in 2009, ''supplementary indicators'' have been allowed indefinitely.
===Chinese characters===
[[Image:PRC Expressway RoadSign Distances.jpg|thumb|200px|[[China|Chinese]] expressway distances [[Expressways of Beijing|road]] sign in eastern [[Beijing]]. Although the primary text is in [[Chinese language|Chinese]], the distances use internationally recognised characters.]]
In [[Japanese language|Japanese]]:
Individual [[Chinese character|Chinese characters]] exist for some SI units, namely metre, litre, and gram, with the prefixes from kilo- (1000) to milli- (1/1000), yielding 21 (3×7) characters. These were [[kokuji|created in Japan]] in the late 19th century ([[Meiji period]]) by choosing characters for the basic units – 米 "metre", 立 "litre", and 瓦 "gram" – and for the prefixes – 千 "kilo-, 1000", 百 "hecto-, 100", 十 "deca-, 10", 分 "deci-, 1/10", 厘 "centi-, 1/100", and 毛 "milli-, 1/1000" – and then combining them to form a single character, such as 粁 (米+千) for kilometre (in the case of no prefix, the base character alone is used). The entire metre series, for example, is 粁, 粨, 籵, 米, 粉, 糎, 粍. The [[symbol]]s for the metric units are internationally-recognised [[Latin characters]].
In [[Chinese language|Chinese]]:
The basic units are 米 mǐ "metre", 升 shēng "litre", 克 kè "gram", and 秒 mǐao "second".
Some sample prefixes are 分 fēn "deci", 厘 lí "centi", 毫 háo "milli", and 微 wēi "micro".
These are not combined into a single character,
so for example centimetres are simply 厘米 límǐ.
==See also==