Perl 5.7.3 and later ships with an adequate set of Chinese encodings,
including the commonly used CP950, CP936 (also known as GBK), Big5
(alias for Big5-Eten), Big5-HKSCS, EUC-CN, HZ, and ISO-IR-165.

However, the numbers of Chinese encodings are staggering, and a complete
coverage will easily increase the size of perl distribution by several
megabytes; hence, this CPAN module tries to provide the rest of them.

If you are using perl 5.8 or later, Encode::CN and Encode::TW will
automatically load the extra encodings for you, so there's no need to
explicitly write use Encode::HanExtra if you are using one of them already.