Background of HKSCS

The popular Chinese characters coding schemes (Big5 and Unicode) use on computers in Hong Kong do not contain all the special Chinese characters used in Hong Kong, which may be names of persons and places, and characters used in the Cantonese dialect. Users may define the characters specific to Hong Kong in the Private Use Area (PUA) of the coding schemes used on their computers. However, such user-defined characters created on a stand-alone computer may not be recognised by other computers on the network, resulting in distortion of information when electronic communication and data exchange in Chinese are conducted across computers.

In order to facilitate electronic communication among government departments, the Hong Kong Government developed a special Chinese character set, which was called the Government Common Character Set (GCCS) in 1995. GCCS is the supplement of the Big5 character set. This character set was initially for internal use by the Government, later on, it was placed in government web sites for the public to download onto their computers.

In 1998, the Information Technology Services Department and the Official Language Agency worked together to revise and enhance the GCCS by collecting other locally specific Chinese characters from various sectors of the community. In collaboration with the Chinese Language Interface Advisory Committee (CLIAC), the Government of the Hong Kong Special Administrative Region (HKSAR) completed the revision of the GCCS in 1999. This revised character set was named Hong Kong Supplementary Character Set (HKSCS) and its first version was published in September 1999. There are two encoding schemes of HKSCS, one scheme is for the Big-5 coding standard and the other is for the ISO 10646 standard. The HKSCS contains 4702 characters.

The latest version of HKSCS, namely HKSCS-2001, was published in December 2001 with additional 116 characters. It technically aligns with the latest version of the ISO 10646 standard, i.e. ISO/IEC 10646-2:2001, published by the International Organisation for Standardisation in November 2001.