The same Han character can have wildly different pronunciations even in a single language (being a logogram, they represent a word and not a sound). KS X 1001,

The same Han character can have wildly different pronunciations even in a single language (being a logogram, they represent a word and not a sound). KS X 1001, the primary Korean character set, even duplicated same characters according to their readings so that they can be almost [1] correctly converted back to Hangul. In practice they didn't work well though, and Unicode assigns all but one duplicate characters into the compatibility region. [1] These readings didn't take account for systematic variations like the initial sound law (두음법칙, for example 이 vs. 리 at the beginning of words).