HKSCS

The Hong Kong Supplementary Character Set (Chinese: 香港增補字符集; commonly abbreviated to HKSCS) is a set of Chinese characters – 4,702 in total in the initial release—used in Cantonese, as well as when writing the names of some places in Hong Kong (whether in written Cantonese or standard written Chinese sentences). It evolved from the preceding Government Chinese Character Set (政府通用字庫) or GCCS. GCCS is a set of supplementary Chinese characters coded in the user-defined areas of the Big5 character set. It was originally used within the Hong Kong Government and later used by the public. It later evolved into Hong Kong Supplementary Character Set when the characters in the set were submitted to ISO-10646 for coding.

Due to the inherent differences between standard written Chinese and written Cantonese, the Government of Hong Kong recognised the need for a standardised set of proprietary characters that would allow for the streamlining of electronic communication; at the time, the Big5 Chinese encoding scheme did not contain a vast majority of these characters (some were erroneously cross-listed with similar characters).

The Government Chinese Character Set (政府通用字庫) or GCCS was thus developed by the government. The character set consists of Chinese characters commonly used in Hong Kong. Some characters are Cantonese-specific, while some are alternative forms of characters. The set is not well-organised and the characters are not closely examined.

Subsequently, the HKSCS-1999 (HKSCS 1999 specification) was developed. Following its acceptance, newer revisions were released in 2001 (adding 116 new characters) and in 2004 (adding 123 new characters), totalling 4,941 characters. 106 GCCS characters were removed in HKSCS-1999 as a result of unification, and their Big5 code points are reserved for compatibility. Retired "not verifiable" GCCS characters are found in UTC Sources (UTC-00877–UTC-00898), where they are sourced from Adobe-CNS1-1, an Adobe-CNS1 supplement implemented to support GCCS.

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