As defined by
RFC 3492, Punycode is a simple and
efficient transfer encoding
syntax designed for use
with Internationalized Domain Names in Applications (IDNA). It uniquely and
reversibly transforms a
Unicode string into an
ASCII string. ASCII characters in the Unicode string
are represented literally, and nonSCII characters are represented by ASCII
characters that are allowed in host name labels (letters, digits, and hyphens).
The RFC 3492 document defines a general algorithm called Bootstring that allows
a string of basic code points to uniquely represent any string of code points
drawn from a larger set. Punycode is an instance of Bootstring that uses
particular parameter values specified by this document, appropriate for IDNA.
