Transliteration is the general process of converting characters from one particular script to another one. This provides a way for people to see personal names or place names in a much more recognizable format.

Broadly speaking, transliteration can also include manipulations of characters within a single script, such as upper- and lowercasing, or producing special symbols. For example, this includes converting typewriter 'straight quotes' and fake dashes (--) to curly quotes and long dashes. It can also be used to convert unfamiliar letters within the same script, such as converting Icelandic THORN (þ) to th. It is very important to note that this transliteration is *not* translation. It is converting the letters from one script to another, not translating the underlying words.

ICU provides a general mechanism for performing transliterations. It includes a set of standard transliterators, such as Greek or Katakana to Latin. Most of these transliterators also have inverse mappings, which convert in the other direction. Filters can also be specified, so that a transliterator only applies to specific characters. Additional transliterators can be easily built from a series of textual rules (at runtime).

Transliterations can also be chained together so that a single operation can perform a series of different transformations.