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Encode::Supported(3)  User Contributed Perl Documentation Encode::Supported(3)


       Encode::Supported -- Encodings supported by Encode


   Encoding Names
       Encoding names are case insensitive. White space in names is ignored.
       In addition, an encoding may have aliases.  Each encoding has one
       "canonical" name.  The "canonical" name is chosen from the names of the
       encoding by picking the first in the following sequence (with a few

       o The name used by the Perl community.  That includes 'utf8' and
         'ascii'.  Unlike aliases, canonical names directly reach the method
         so such frequently used words like 'utf8' don't need to do alias

       o The MIME name as defined in IETF RFCs.  This includes all "iso-"s.

       o The name in the IANA registry.

       o The name used by the organization that defined it.

       In case de jure canonical names differ from that of the Encode module,
       they are always aliased if it ever be implemented.  So you can safely
       tell if a given encoding is implemented or not just by passing the
       canonical name.

       Because of all the alias issues, and because in the general case
       encodings have state, "Encode" uses an encoding object internally once
       an operation is in progress.

Supported Encodings

       As of Perl 5.8.0, at least the following encodings are recognized.
       Note that unless otherwise specified, they are all case insensitive
       (via alias) and all occurrence of spaces are replaced with '-'.  In
       other words, "ISO 8859 1" and "iso-8859-1" are identical.

       Encodings are categorized and implemented in several different modules
       but you don't have to "use Encode::XX" to make them available for most
       cases. will automatically load those modules on demand.

   Built-in Encodings
       The following encodings are always available.

         Canonical     Aliases                      Comments & References
         ascii         US-ascii ISO-646-US                         [ECMA]
         ascii-ctrl                                      Special Encoding
         iso-8859-1    latin1                                       [ISO]
         null                                            Special Encoding
         utf8          UTF-8                                    [RFC2279]

       null and ascii-ctrl are special.  "null" fails for all character so
       when you set fallback mode to PERLQQ, HTMLCREF or XMLCREF, ALL
       CHARACTERS will fall back to character references.  Ditto for "ascii-
       ctrl" except for control characters.  For fallback modes, see Encode.

   Encode::Unicode -- other Unicode encodings
       Unicode coding schemes other than native utf8 are supported by
       Encode::Unicode, which will be autoloaded on demand.

         UCS-2BE       UCS-2, iso-10646-1                      [IANA, UC]
         UCS-2LE                                                     [UC]
         UTF-16                                                      [UC]
         UTF-16BE                                                    [UC]
         UTF-16LE                                                    [UC]
         UTF-32                                                      [UC]
         UTF-32BE      UCS-4                                         [UC]
         UTF-32LE                                                    [UC]
         UTF-7                                                  [RFC2152]

       To find how (UCS-2|UTF-(16|32))(LE|BE)? differ from one another, see

       UTF-7 is a special encoding which "re-encodes" UTF-16BE into a 7-bit
       encoding.  It is implemented separately by Encode::Unicode::UTF7.

   Encode::Byte -- Extended ASCII
       Encode::Byte implements most single-byte encodings except for Symbols
       and EBCDIC. The following encodings are based on single-byte encodings
       implemented as extended ASCII.  Most of them map \x80-\xff (upper half)
       to non-ASCII characters.

       ISO-8859 and corresponding vendor mappings
         Since there are so many, they are presented in table format with
         languages and corresponding encoding names by vendors.  Note that the
         table is sorted in order of ISO-8859 and the corresponding vendor
         mappings are slightly different from that of ISO.  See
         <> for details.

           Lang/Regions  ISO/Other Std.  DOS     Windows Macintosh  Others
           N. America    (ASCII)         cp437        AdobeStandardEncoding
                                         cp863 (DOSCanadaF)
           W. Europe     iso-8859-1      cp850   cp1252  MacRoman  nextstep
                                         cp860 (DOSPortuguese)
           Cntrl. Europe iso-8859-2      cp852   cp1250  MacCentralEurRoman
           Latin3[1]     iso-8859-3
           Latin4[2]     iso-8859-4
           Cyrillics     iso-8859-5      cp855   cp1251  MacCyrillic
             (See also next section)     cp866           MacUkrainian
           Arabic        iso-8859-6      cp864   cp1256  MacArabic
                                         cp1006          MacFarsi
           Greek         iso-8859-7      cp737   cp1253  MacGreek
                                         cp869 (DOSGreek2)
           Hebrew        iso-8859-8      cp862   cp1255  MacHebrew
           Turkish       iso-8859-9      cp857   cp1254  MacTurkish
           Nordics       iso-8859-10     cp865
                                         cp861           MacIcelandic
           Thai          iso-8859-11[3]  cp874           MacThai
           (iso-8859-12 is nonexistent. Reserved for Indics?)
           Baltics       iso-8859-13     cp775           cp1257
           Celtics       iso-8859-14
           Latin9 [4]    iso-8859-15
           Latin10       iso-8859-16
           Vietnamese    viscii                  cp1258  MacVietnamese

           [1] Esperanto, Maltese, and Turkish. Turkish is now on 8859-9.
           [2] Baltics.  Now on 8859-10, except for Latvian.
           [3] TIS 620 +  Non-Breaking Space (0xA0 / U+00A0)
           [4] Nicknamed Latin0; the Euro sign as well as French and Finnish
               letters that are missing from 8859-1 were added.

         All cp* are also available as ibm-*, ms-*, and windows-* .  See also

         Macintosh encodings don't seem to be registered in such entities as
         IANA.  "Canonical" names in Encode are based upon Apple's Tech Note
         1150.  See <> for

       KOI8 - De Facto Standard for the Cyrillic world
         Though ISO-8859 does have ISO-8859-5, the KOI8 series is far more
         popular in the Net.   Encode comes with the following KOI charsets.
         For gory details, see <>

           koi8-r cp878                                           [RFC1489]
           koi8-u                                                 [RFC2319]

   gsm0338 - Hentai Latin 1
       GSM0338 is for GSM handsets. Though it shares alphanumerals with ASCII,
       control character ranges and other parts are mapped very differently,
       mainly to store Greek characters.  There are also escape sequences
       (starting with 0x1B) to cover e.g. the Euro sign.

       This was once handled by Encode::Bytes but because of all those unusual
       specifications, Encode 2.20 has relocated the support to
       Encode::GSM0338. See Encode::GSM0338 for details.

       gsm0338 support before 2.19
         Some special cases like a trailing 0x00 byte or a lone 0x1B byte are
         not well-defined and decode() will return an empty string for them.
         One possible workaround is

            $gsm =~ s/\x00\z/\x00\x00/;
            $uni = decode("gsm0338", $gsm);
            $uni .= "\xA0" if $gsm =~ /\x1B\z/;

         Note that the Encode implementation of GSM0338 does not implement the
         reuse of Latin capital letters as Greek capital letters (for example,
         the 0x5A is U+005A (LATIN CAPITAL LETTER Z), not U+0396 (GREEK

         The GSM0338 is also covered in Encode::Byte even though it is not an
         "extended ASCII" encoding.

   CJK: Chinese, Japanese, Korean (Multibyte)
       Note that Vietnamese is listed above.  Also read "Encoding vs Charset"
       below.  Also note that these are implemented in distinct modules by
       countries, due to the size concerns (simplified Chinese is mapped to
       'CN', continental China, while traditional Chinese is mapped to 'TW',
       Taiwan).  Please refer to their respective documentation pages.

       Encode::CN -- Continental China
           Standard      DOS/Win Macintosh                Comment/Reference
           euc-cn [1]            MacChineseSimp
           (gbk)         cp936 [2]
           gb12345-raw                      { GB12345 without CES }
           gb2312-raw                       { GB2312  without CES }

           [1] GB2312 is aliased to this.  See L<Microsoft-related naming mess>
           [2] gbk is aliased to this.  See L<Microsoft-related naming mess>

       Encode::JP -- Japan
           Standard      DOS/Win Macintosh                Comment/Reference
           shiftjis      cp932   macJapanese
           iso-2022-jp                                            [RFC1468]
           iso-2022-jp-1                                          [RFC2237]
           jis0201-raw  { JIS X 0201 (roman + halfwidth kana) without CES }
           jis0208-raw  { JIS X 0208 (Kanji + fullwidth kana) without CES }
           jis0212-raw  { JIS X 0212 (Extended Kanji)         without CES }

       Encode::KR -- Korea
           Standard      DOS/Win Macintosh                Comment/Reference
           euc-kr                MacKorean                        [RFC1557]
                         cp949 [1]
           iso-2022-kr                                            [RFC1557]
           johab                                  [KS X 1001:1998, Annex 3]
           ksc5601-raw                              { KSC5601 without CES }

           [1] ks_c_5601-1987, (x-)?windows-949, and uhc are aliased to this.
           See below.

       Encode::TW -- Taiwan
           Standard      DOS/Win Macintosh                Comment/Reference
           big5-eten     cp950   MacChineseTrad {big5 aliased to big5-eten}

       Encode::HanExtra -- More Chinese via CPAN
         Due to the size concerns, additional Chinese encodings below are
         distributed separately on CPAN, under the name Encode::HanExtra.

           Standard      DOS/Win Macintosh                Comment/Reference
           big5ext                                   CMEX's Big5e Extension
           big5plus                                  CMEX's Big5+ Extension
           cccii         Chinese Character Code for Information Interchange
           euc-tw                             EUC (Extended Unix Character)
           gb18030                          GBK with Traditional Characters

       Encode::JIS2K -- JIS X 0213 encodings via CPAN
         Due to size concerns, additional Japanese encodings below are
         distributed separately on CPAN, under the name Encode::JIS2K.

           Standard      DOS/Win Macintosh                Comment/Reference

   Miscellaneous encodings
         See perlebcdic for details.


         For symbols  and dingbats.


         Strictly speaking, MIME header encoding documented in RFC 2047 is
         more of encapsulation than encoding.  However, their support in
         modern world is imperative so they are supported.

           MIME-Header                                            [RFC2047]
           MIME-B                                                 [RFC2047]
           MIME-Q                                                 [RFC2047]

         This one is not a name of encoding but a utility that lets you pick
         up the most appropriate encoding for a data out of given suspects.
         See Encode::Guess for details.

Unsupported encodings

       The following encodings are not supported as yet; some because they are
       rarely used, some because of technical difficulties.  They may be
       supported by external modules via CPAN in the future, however.

       ISO-2022-JP-2 [RFC1554]
         Not very popular yet.  Needs Unicode Database or equivalent to
         implement encode() (because it includes JIS X 0208/0212, KSC5601, and
         GB2312 simultaneously, whose code points in Unicode overlap.  So you
         need to lookup the database to determine to what character set a
         given Unicode character should belong).

       ISO-2022-CN [RFC1922]
         Not very popular.  Needs CNS 11643-1 and -2 which are not available
         in this module.  CNS 11643 is supported (via euc-tw) in
         Encode::HanExtra.  Audrey Tang may add support for this encoding in
         her module in future.

       Various HP-UX encodings
         The following are unsupported due to the lack of mapping data.

           '8'  - arabic8, greek8, hebrew8, kana8, thai8, and turkish8
           '15' - japanese15, korean15, and roi15

       Cyrillic encoding ISO-IR-111
         Anton Tagunov doubts its usefulness.

       ISO-8859-8-1 [Hebrew]
         None of the Encode team knows Hebrew enough (ISO-8859-8, cp1255 and
         MacHebrew are supported because and just because there were mappings
         available at <>).  Contributions welcome.

       ISIRI 3342, Iran System, ISIRI 2900 [Farsi]

       Thai encoding TCVN

       Vietnamese encodings VPS
         Though Jungshik Shin has reported that Mozilla supports this
         encoding, it was too late before 5.8.0 for us to add it.  In the
         future, it may be available via a separate module.  See
         if you are interested in helping us.

       Various Mac encodings
         The following are unsupported due to the lack of mapping data.

           MacArmenian,  MacBengali,   MacBurmese,   MacEthiopic
           MacExtArabic, MacGeorgian,  MacKannada,   MacKhmer
           MacLaotian,   MacMalayalam, MacMongolian, MacOriya
           MacSinhalese, MacTamil,     MacTelugu,    MacTibetan

         The rest which are already available are based upon the vendor
         mappings at <> .

       (Mac) Indic encodings
         The maps for the following are available at <>
         but remain unsupported because those encodings need an algorithmical
         approach, currently unsupported by enc2xs:


         For details, please see "Unicode mapping issues and notes:" at
         <> .

         I believe this issue is prevalent not only for Mac Indics but also in
         other Indic encodings, but the above were the only Indic encodings
         maps that I could find at <> .

Encoding vs. Charset -- terminology

       We are used to using the term (character) encoding and character set
       interchangeably.  But just as confusing the terms byte and character is
       dangerous and the terms should be differentiated when needed, we need
       to differentiate encoding and character set.

       To understand that, here is a description of how we make computers grok
       our characters.

       o First we start with which characters to include.  We call this
         collection of characters character repertoire.

       o Then we have to give each character a unique ID so your computer can
         tell the difference between 'a' and 'A'.  This itemized character
         repertoire is now a character set.

       o If your computer can grow the character set without further
         processing, you can go ahead and use it.  This is called a coded
         character set (CCS) or raw character encoding.  ASCII is used this
         way for most cases.

       o But in many cases, especially multi-byte CJK encodings, you have to
         tweak a little more.  Your network connection may not accept any data
         with the Most Significant Bit set, and your computer may not be able
         to tell if a given byte is a whole character or just half of it.  So
         you have to encode the character set to use it.

         A character encoding scheme (CES) determines how to encode a given
         character set, or a set of multiple character sets.  7bit ISO-2022 is
         an example of a CES.  You switch between character sets via escape

       Technically, or mathematically, speaking, a character set encoded in
       such a CES that maps character by character may form a CCS.  EUC is
       such an example.  The CES of EUC is as follows:

       o Map ASCII unchanged.

       o Map such a character set that consists of 94 or 96 powered by N
         members by adding 0x80 to each byte.

       o You can also use 0x8e and 0x8f to indicate that the following
         sequence of characters belongs to yet another character set.  To each
         following byte is added the value 0x80.

       By carefully looking at the encoded byte sequence, you can find that
       the byte sequence conforms a unique number.  In that sense, EUC is a
       CCS generated by a CES above from up to four CCS (complicated?).  UTF-8
       falls into this category.  See "UTF-8" in perlUnicode to find out how
       UTF-8 maps Unicode to a byte sequence.

       You may also have found out by now why 7bit ISO-2022 cannot comprise a
       CCS.  If you look at a byte sequence \x21\x21, you can't tell if it is
       two !'s or IDEOGRAPHIC SPACE.  EUC maps the latter to \xA1\xA1 so you
       have no trouble differentiating between "!!". and "  ".

Encoding Classification (by Anton Tagunov and Dan Kogai)

       This section tries to classify the supported encodings by their
       applicability for information exchange over the Internet and to choose
       the most suitable aliases to name them in the context of such

       o To (en|de)code encodings marked by "(**)", you need
         "Encode::HanExtra", available from CPAN.

       Encoding names

         US-ASCII    UTF-8    ISO-8859-*  KOI8-R
         Shift_JIS   EUC-JP   ISO-2022-JP ISO-2022-JP-1
         EUC-KR      Big5     GB2312

       are registered with IANA as preferred MIME names and may be used over
       the Internet.

       "Shift_JIS" has been officialized by JIS X 0208:1997. "Microsoft-
       related naming mess" gives details.

       "GB2312" is the IANA name for "EUC-CN".  See "Microsoft-related naming
       mess" for details.

       "GB_2312-80" raw encoding is available as "gb2312-raw" with Encode. See
       Encode::CN for details.

         KOI8-U        [RFC2319]

       have not been registered with IANA (as of March 2002) but seem to be
       supported by major web browsers.  The IANA name for "EUC-CN" is


       is heavily misused.  See "Microsoft-related naming mess" for details.

       "KS_C_5601-1987" raw encoding is available as "kcs5601-raw" with
       Encode. See Encode::KR for details.

         UTF-16 UTF-16BE UTF-16LE

       are IANA-registered "charset"s. See [RFC 2781] for details.  Jungshik
       Shin reports that UTF-16 with a BOM is well accepted by MS IE 5/6 and
       NS 4/6. Beware however that

       o "UTF-16" support in any software you're going to be
         using/interoperating with has probably been less tested then "UTF-8"

       o "UTF-8" coded data seamlessly passes traditional command piping
         ("cat", "more", etc.) while "UTF-16" coded data is likely to cause
         confusion (with its zero bytes, for example)

       o it is beyond the power of words to describe the way HTML browsers
         encode non-"ASCII" form data. To get a general impression, visit
         <>.  While
         encoding of form data has stabilized for "UTF-8" encoded pages (at
         least IE 5/6, NS 6, and Opera 6 behave consistently), be sure to
         expect fun (and cross-browser discrepancies) with "UTF-16" encoded

       The rule of thumb is to use "UTF-8" unless you know what you're doing
       and unless you really benefit from using "UTF-16".

         ISO-IR-165    [RFC1345]
         GB 12345
         GB 18030 (**)  (see links below)
         EUC-TW   (**)

       are totally valid encodings but not registered at IANA. The names under
       which they are listed here are probably the most widely-known names for
       these encodings and are recommended names.

         BIG5PLUS (**)

       is a proprietary name.

   Microsoft-related naming mess
       Microsoft products misuse the following names:

         Microsoft extension to "EUC-KR".

         Proper names: "CP949", "UHC", "x-windows-949" (as used by Mozilla).

         for details.

         Encode aliases "KS_C_5601-1987" to "cp949" to reflect this common
         misusage. Raw "KS_C_5601-1987" encoding is available as

         See Encode::KR for details.

         Microsoft extension to "EUC-CN".

         Proper names: "CP936", "GBK".

         "GB2312" has been registered in the "EUC-CN" meaning at IANA. This
         has partially repaired the situation: Microsoft's "GB2312" has become
         a superset of the official "GB2312".

         Encode aliases "GB2312" to "euc-cn" in full agreement with IANA
         registration. "cp936" is supported separately.  Raw "GB_2312-80"
         encoding is available as "gb2312-raw".

         See Encode::CN for details.

         Microsoft extension to "Big5".

         Proper name: "CP950".

         Encode separately supports "Big5" and "cp950".

         Microsoft's understanding of "Shift_JIS".

         JIS has not endorsed the full Microsoft standard however.  The
         official "Shift_JIS" includes only JIS X 0201 and JIS X 0208
         character sets, while Microsoft has always used "Shift_JIS" to encode
         a wider character repertoire. See "IANA" registration for

         As a historical predecessor, Microsoft's variant probably has more
         rights for the name, though it may be objected that Microsoft
         shouldn't have used JIS as part of the name in the first place.

         Unambiguous name: "CP932". "IANA" name (also used by Mozilla, and
         provided as an alias by Encode): "Windows-31J".

         Encode separately supports "Shift_JIS" and "cp932".


       character repertoire
         A collection of unique characters.  A character set in the strictest
         sense. At this stage, characters are not numbered.

       coded character set (CCS)
         A character set that is mapped in a way computers can use directly.
         Many character encodings, including EUC, fall in this category.

       character encoding scheme (CES)
         An algorithm to map a character set to a byte sequence.  You don't
         have to be able to tell which character set a given byte sequence
         belongs.  7-bit ISO-2022 is a CES but it cannot be a CCS.  EUC is an
         example of being both a CCS and CES.

       charset (in MIME context)
         has long been used in the meaning of "encoding", CES.

         While the word combination "character set" has lost this meaning in
         MIME context since [RFC 2130], the "charset" abbreviation has
         retained it. This is how [RFC 2277] and [RFC 2278] bless "charset":

          This document uses the term "charset" to mean a set of rules for
          mapping from a sequence of octets to a sequence of characters, such
          as the combination of a coded character set and a character encoding
          scheme; this is also what is used as an identifier in MIME "charset="
          parameters, and registered in the IANA charset registry ...  (Note
          that this is NOT a term used by other standards bodies, such as ISO).
          [RFC 2277]

         Extended Unix Character.  See ISO-2022.

         A CES that was carefully designed to coexist with ASCII.  There are a
         7 bit version and an 8 bit version.

         The 7 bit version switches character set via escape sequence so it
         cannot form a CCS.  Since this is more difficult to handle in
         programs than the 8 bit version, the 7 bit version is not very
         popular except for iso-2022-jp, the de facto standard CES for

         The 8 bit version can form a CCS.  EUC and ISO-8859 are two examples
         thereof.  Pre-5.6 perl could use them as string literals.

         Short for Universal Character Set.  When you say just UCS, it means

         ISO/IEC 10646 encoding form: Universal Character Set coded in two

         A character set that aims to include all character repertoires of the
         world.  Many character sets in various national as well as industrial
         standards have become, in a way, just subsets of Unicode.

         Short for Unicode Transformation Format.  Determines how to map a
         Unicode character into a byte sequence.

         A UTF in 16-bit encoding.  Can either be in big endian or little
         endian.  The big endian version is called UTF-16BE (equal to UCS-2 +
         surrogate support) and the little endian version is called UTF-16LE.

See Also

       Encode(3), Encode::Byte(3), Encode::CN(3), Encode::JP(3), Encode::KR(3),
       Encode::TW(3), Encode::EBCDIC(3), Encode::Symbol(3), Encode::MIME::Header(3),


         European Computer Manufacturers Association <>

         ECMA-035 (eq "ISO-2022")

           The specification of ISO-2022 is available from the link above.

         Internet Assigned Numbers Authority <>

         Assigned Charset Names by IANA

           Most of the "canonical names" in Encode derive from this list so
           you can directly apply the string you have extracted from MIME
           header of mails and web pages.

         International Organization for Standardization <>

         Request For Comments -- need I say more?
         <>, <>,

         Unicode Consortium <>

         Unicode Glossary

           The glossary of this document is based upon this site.

   Other Notable Sites

         Contains a lot of useful information, especially gory details of ISO
         vs. vendor mappings.


         Somewhat obsolete (last update in 1996), but still useful.  Also try


         You will find brief info on "EUC-CN", "GBK" and mostly on "GB 18030".

       Jungshik Shin's Hangul FAQ

         And especially its subject 8.


         A comprehensive overview of the Korean ("KS *") standards. "Introduction to i18n"
         A brief description for most of the mentioned CJK encodings is
         contained in

   Offline sources
       "CJKV Information Processing" by Ken Lunde
         CJKV Information Processing 1999 O'Reilly & Associates, ISBN :

         The modern successor of "CJK.inf".

         Features a comprehensive coverage of CJKV character sets and
         encodings along with many other issues faced by anyone trying to
         better support CJKV languages/scripts in all the areas of information

         To purchase this book, visit
         <> or your favourite

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