The Yen sign appears as a backslash

With one of the character encodings listed below, a halfwidth Yen character (¥) is displayed as is when you type, but if you change the encoding, or, if you save and reopen the file, it will be displayed as a backslash (\).

Japanese (Windows, DOS)Arabic (Mac OS)Central European (ISO Latin 2)
Japanese (EUC)Hebrew (Mac OS)Western (ISO Latin 3)
Traditional Chinese (EUC)Greek (ISO 8859-7)Central European (ISO Latin 4)
Simplified Chinese (EUC)Cyrillic (Mac OS)Latin-US (DOS)
Korean (EUC)Cyrillic (ISO 8859-5)Central European (Windows Latin 2)
Korean (Windows, DOS)Central European (Mac OS)