Where are private use characters used, and how should they be handled?
Private use characters (also known as user defined characters) are used commonly in East Asia, particularly Japan, China, and Korea, to extend the available characters in various national standard and vendor character sets. The Unicode Standard also makes provision for private use characters. Since the Unicode Standard includes so many more standard characters than any other character encoding, there is less of a requirement for private use characters than in a typical legacy character set; however, there are occasionally cases where characters that are not yet in the standard need to be represented by codepoints in the Private Use Area (PUA). Some private use characters may never get standard encodings for one reason or another. Also, a particular implementation may choose to use private use characters for specific internal purposes. It is relatively easy for Input Method Editors (IME) to allow private use characters to be added in the PUA, keeping track of the text sequence that shou
