Editing ASCII (section)

===Unicode===
{{Main|Unicode|ISO/IEC 10646}}{{See also|Basic Latin (Unicode block)}}
[[Unicode]] and the ISO/IEC 10646 [[Universal Character Set]] (UCS) have a much wider array of characters and their various encoding forms have begun to supplant ISO/IEC 8859 and ASCII rapidly in many environments. While ASCII is limited to 128 characters, Unicode and the UCS support more characters by separating the concepts of unique identification (using [[natural number]]s called ''code points'') and encoding (to 8-, 16-, or 32-bit binary formats, called [[UTF-8]], [[UTF-16]], and [[UTF-32]], respectively).

ASCII was incorporated into the Unicode (1991) character set as the first 128 symbols, so the 7-bit ASCII characters have the same numeric codes in both sets. This allows [[UTF-8]] to be [[Backward compatibility|backward compatible]] with 7-bit ASCII, as a UTF-8 file containing only ASCII characters is identical to an ASCII file containing the same sequence of characters.  Even more importantly, [[forward compatibility]] is ensured as software that recognizes only 7-bit ASCII characters as special and does not alter bytes with the highest bit set (as is often done to support 8-bit ASCII extensions such as ISO-8859-1) will preserve UTF-8 data unchanged.<ref>{{cite web |title=utf-8(7)&nbsp;– Linux manual page |publisher=Man7.org |date=2014-02-26 |url=http://man7.org/linux/man-pages/man7/utf-8.7.html |access-date=2014-04-21 |archive-url=https://web.archive.org/web/20140422232059/http://man7.org/linux/man-pages/man7/utf-8.7.html |archive-date=April 22, 2014 |url-status=live }}</ref>