*  Recognized character sets include:
 *
 *     string for 'O'ptions Menu          MIME name
 *     ===========================        =========
 *     7 bit approximations (US-ASCII)    us-ascii
 *     Western (ISO-8859-1)               iso-8859-1
 *     Western (cp850)                    cp850
 *     Western (windows-1252)             windows-1252
 *     IBM PC US codepage (cp437)         cp437
 *     DEC Multinational                  dec-mcs
 *     Macintosh (8 bit)                  macintosh
 *     NeXT character set                 next
 *     HP Roman8                          hp-roman8
 *     Chinese                            euc-cn
 *     Japanese (EUC-JP)                  euc-jp
 *     Japanese (Shift_JIS)               shift_jis
 *     Korean                             euc-kr
 *     Taipei (Big5)                      big5
 *     Vietnamese (VISCII)                viscii
 *     Eastern European (ISO-8859-2)      iso-8859-2
 *     Eastern European (cp852)           cp852
 *     Eastern European (windows-1250)    windows-1250
 *     Latin 3 (ISO-8859-3)               iso-8859-3
 *     Latin 4 (ISO-8859-4)               iso-8859-4
 *     Baltic Rim (cp775)                 cp775
 *     Baltic Rim (windows-1257)          windows-1257
 *     Cyrillic (ISO-8859-5)              iso-8859-5
 *     Cyrillic (cp866)                   cp866
 *     Cyrillic (windows-1251)            windows-1251
 *     Cyrillic (KOI8-R)                  koi8-r
 *     Arabic (ISO-8859-6)                iso-8859-6
 *     Arabic (cp864)                     cp864
 *     Arabic (windows-1256)              windows-1256
 *     Greek (ISO-8859-7)                 iso-8859-7
 *     Greek (cp737)                      cp737
 *     Greek2 (cp869)                     cp869
 *     Greek (windows-1253)               windows-1253
 *     Hebrew (ISO-8859-8)                iso-8859-8
 *     Hebrew (cp862)                     cp862
 *     Hebrew (windows-1255)              windows-1255
 *     Turkish (ISO-8859-9)               iso-8859-9
 *     ISO-8859-10                        iso-8859-10
 *     Ukrainian Cyrillic (cp866u)        cp866u
 *     Ukrainian Cyrillic (KOI8-U)        koi8-u
 *     UNICODE (UTF-8)                    utf-8
 *     RFC 1345 w/o Intro                 mnemonic+ascii+0
 *     RFC 1345 Mnemonic                  mnemonic
 *     Transparent                        x-transparent