<P> Because the full English alphabet and the most - used characters in English are included in the seven - bit code points of ASCII, which are common to all encodings (even most proprietary encodings), English - language text is less damaged by interpreting it with the wrong encoding, but text in other languages can display as mojibake (complete nonsense). Because many Internet standards use ISO 8859 - 1, and because Microsoft Windows (using the code page 1252 superset of ISO 8859 - 1) is the dominant operating system for personal computers today, unannounced use of ISO 8859 - 1 is quite commonplace, and may generally be assumed unless there are indications otherwise . </P> <P> Many communications protocols, most importantly SMTP and HTTP, require the character encoding of content to be tagged with IANA - assigned character set identifiers . </P> <P> Some multi-byte character encodings (character encodings that can handle more than 256 different characters) are also true extended ASCII . That means all ASCII characters are encoded with a single byte with the value that is used in ASCII to encode that character . They can be used in file formats where only ASCII bytes are used for keywords and file format syntax, while bytes 0x80 - 0xFF might be used for free text, including most programming languages, where language keywords, variable names, and function names must be in ASCII, but string constants and comments can use non-ASCII characters . This makes it much easier to introduce a multi-byte character set into existing systems that use extended ASCII . </P> <P> UTF - 8 is true extended ASCII, as are some Extended Unix Code encodings . </P>

How many bytes did each character require for extended ascii characters