Internal Code

The term internal code is a word-for-word translation of the Chinese term neima (內碼, 内码; pinyin: nèimă; jyutping: noi6 maa5). The term is primarily used by Chinese people.

Originally referring to the encoding used “internally” by a Chinese system, it refers to the encoding of a character in some character set, or to the character encoding being used. It is not an encoding in itself, and the actual encoding being referred to has to be determined by context.

On any computer system, the internal code is the native encoding being used. For example, in a Big5-based system (e.g., Microsoft Windows 3.1 localized for traditional Chinese), the internal code is Big5; similarly, in a GB-based system (e.g., DOS running CCDOS), the internal code would be GB2312. On many modern operating systems (such as all modern Microsoft Windows systems), the internal code is a form of Unicode.

Within a particular encoding, the internal code of a certain character simply means the value of the code point used to represent that character. For example, in the Big5 encoding, the character "一" (Chinese, lit. one) has the internal code of A440 (hexadecimal); in the GB encoding, the same character has the internal code of D2BB.