The concept of reserving specific code points for Private Use is based on similar earlier usage in other character sets. In particular, many otherwise obsolete characters in East Asian scripts continue to be used in specific names or other situations, and so some character sets for those scripts made allowance for private-use characters (such as the user-defined planes of CNS 11643, or "gaiji" in certain Japanese encodings). The Unicode standard references these uses under the name "End User Character Definition" (EUCD).