HKSCS

The Hong Kong Special Character Set (commonly abbreviated to HKSCS) is a set of Chinese characters -- 4,702 in total in the initial release -- used exclusively in Cantonese.

Due to the inherent differences between Mandarin and Cantonese, the Hong Kong government recognized the need for a standardized set of "proprietary" characters that would allow for the streamlining of electronic communication; at the time, the Big-5 Chinese encoding scheme did not contain a vast majority of these characters (some were erroneously cross-listed with similar characters). Subsequently, the HKSCS-1999 (HKSCS 1999 specification) was born. Following its acceptance, a newer revision was released in 2001, adding 116 new characters.

The HKSCS is currently supported by Big-5 and the ISO 10646.