character coding system
Technical term used in computing and information processing for a system that assigns codes to characters.
This character coding system covers all Japanese kanji.
文字コード is a more common term for 'character code' or 'character encoding', while 文字符号系 is a broader, more formal term for the entire coding system.
Compound of 文字 (character), 符号 (code), and 系 (system). The exact derivation is uncertain; it is a modern technical term.