KEIS (Kanji-processing Extended Information System) is an EBCDIC encoding used by Hitachi, with double-byte characters (a DBCS-Host encoding) included using shifting sequences, making it a stateful encoding. Specifically, the sequence switches to single-byte mode and the sequence switches to double-byte mode. However, JIS X 0208 characters are encoded using the same byte sequences used to encode them in EUC-JP. This results in duplicate encodings for the —0x4040 per the DBCS-Host code structure, and 0xA1A1 as in EUC-JP. This differs from IBM's DBCS-Host encoding for Japanese, the layout of which builds on versions which predate JIS X 0208 altogether. The lead byte range is extended back to 0x59, out of which the lead bytes 0x81–A0 are designated for user-defined characters, and the remainder are used for corporate-defined characters, including both kanji and non-kanji.