Most Windows text files use "ANSI", "OEM", "Unicode" or "UTF-8" encoding. What Windows terminology calls "ANSI encodings" are usually single-byte ISO-8859 encodings (i.e. ANSI in the Microsoft Notepad menus is really "System Code Page", non-Unicode, legacy encoding), except for in locales such as Chinese, Japanese and Korean that require double-byte character sets. ANSI encodings were traditionally used as default system locales within Windows, before the transition to Unicode. By contrast, OEM encodings, also known as MS-DOS code pages, were defined by IBM for use in the original IBM PC text mode display system. They typically include graphical and line-drawing characters common in (possibly full-screen) MS-DOS applications. "Unicode"-encoded Windows text files contain text in UTF-16 Unicode Transformation Format. Such files normally begin with Byte Order Mark (BOM), which communicates the endianness of the file content. Although UTF-8 does not suffer from endianness problems, many Windows programs (i.e. Notepad) prepend the contents of UTF-8-encoded files with BOM, to differentiate UTF-8 encoding from other 8-bit encodings.