ISO/IEC 10646
When writing Taiwanese in Han characters, some writers create 'new' characters when they consider it is impossible to use directly or borrow existing ones; this corresponds to similar practices in character usage in Cantonese, Vietnamese chữ nôm, Korean hanja and Japanese kanji. These are usually not encoded in Unicode (or the corresponding ISO/IEC 10646: Universal Character Set), thus creating problems in computer processing.