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UTF8(5)			  FreeBSD File Formats Manual		       UTF8(5)

NAME
     utf8 -- UTF-8, a transformation format of ISO 10646

SYNOPSIS
     ENCODING "UTF-8"

DESCRIPTION
     The UTF-8 encoding	represents UCS-4 characters as a sequence of octets,
     using between 1 and 6 for each character.	It is backwards	compatible
     with ASCII, so 0x00-0x7f refer to the ASCII character set.	 The multibyte
     encoding of non-ASCII characters consist entirely of bytes	whose high
     order bit is set.	The actual encoding is represented by the following
     table:

     [0x00000000 - 0x0000007f] [00000000.0bbbbbbb] -> 0bbbbbbb
     [0x00000080 - 0x000007ff] [00000bbb.bbbbbbbb] -> 110bbbbb,	10bbbbbb
     [0x00000800 - 0x0000ffff] [bbbbbbbb.bbbbbbbb] ->
	     1110bbbb, 10bbbbbb, 10bbbbbb
     [0x00010000 - 0x001fffff] [00000000.000bbbbb.bbbbbbbb.bbbbbbbb] ->
	     11110bbb, 10bbbbbb, 10bbbbbb, 10bbbbbb
     [0x00200000 - 0x03ffffff] [000000bb.bbbbbbbb.bbbbbbbb.bbbbbbbb] ->
	     111110bb, 10bbbbbb, 10bbbbbb, 10bbbbbb, 10bbbbbb
     [0x04000000 - 0x7fffffff] [0bbbbbbb.bbbbbbbb.bbbbbbbb.bbbbbbbb] ->
	     1111110b, 10bbbbbb, 10bbbbbb, 10bbbbbb, 10bbbbbb, 10bbbbbb

     If	more than a single representation of a value exists (for example,
     0x00; 0xC0	0x80; 0xE0 0x80	0x80) the shortest representation is always
     used.  Longer ones	are detected as	an error as they pose a	potential
     security risk, and	destroy	the 1:1	character:octet	sequence mapping.

SEE ALSO
     euc(5)

     Rob Pike and Ken Thompson,	"Hello World", Proceedings of the Winter 1993
     USENIX Technical Conference, USENIX Association, January 1993.

     F.	Yergeau, UTF-8,	a transformation format	of ISO 10646, January 1998,
     RFC 2279.

     The Unicode Standard, Version 3.0,	The Unicode Consortium,	2000, as
     amended by	the Unicode Standard Annex #27:	Unicode	3.1 and	by the Unicode
     Standard Annex #28: Unicode 3.2.

STANDARDS
     The utf8 encoding is compatible with RFC 2279 and Unicode 3.2.

FreeBSD	10.1			 April 7, 2004			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | STANDARDS

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