Transliteration Concepts

There are a number of generally desirable qualities for script transliterations. A good transliteration should be:

  • Complete
  • Predictable
  • Pronounceable
  • Unambiguous

These qualities are rarely satisfied simultaneously, so the Transliterator stage attempts to balance these requirements.


Every well-formed sequence of characters in the source script should transliterate to a sequence of characters from the target script.


The letters themselves (without any knowledge of the languages written in that script) should be sufficient for the transliteration, based on a relatively small number of rules. This allows the transliteration to be performed mechanically.


Transliteration is not as useful if the process simply maps the characters without any regard to their pronunciation. Simply mapping "αβγδεζηθ..." to "abcdefgh..." would yield strings that might be complete and unambiguous, but cannot be pronounced.

Standard transliteration methods often do not follow the pronunciation rules of any particular language in the target script. For example, the Japanese Hepburn system uses a "j" that has the English phonetic value (as opposed to French, German, or Spanish), but uses vowels that do not have the standard English sounds. A transliteration method might also require some special knowledge to have the correct pronunciation. For example, in the Japanese kunrei-siki system, "tu" is pronounced as "tsu". This is similar to situations where there are different languages within the same script. For example, knowing that the word Gewalt comes from German allows a knowledgeable reader to pronounce the "w" as a "v".

In some cases, transliteration may be heavily influenced by tradition. For example, the modern Greek letter beta (β) sounds like a "v", but a transform may continue to use a b (as in biology). In that case, the user would need to know that a "b" in the transliterated word corresponded to beta (β) and is to be pronounced as a "v" in modern Greek. Letters may also be transliterated differently according to their context to make the pronunciation more predictable. For example, since the Greek sequence GAMMA GAMMA (γγ) is pronounced as "ng", the first GAMMA can be transcribed as an "n".

Note: In general, in order to produce predictable results when transliterating Latin script to other scripts, English text will not produce phonetic results. This is because the pronunciation of English cannot be predicted easily from the letters in a word. For example, grove, move, and love all end with "ove", but are pronounced very differently.


It should always be possible to recover the text in the source script from the transliteration in the target script. For example, it should be possible to go from Elláda back to the original Ελλάδα. However, in transliteration multiple characters can produce ambiguities. For example, the Greek character PSI (ψ) maps to ps, but ps could also result from the sequence PI, SIGMA (πσ) since PI (π) maps to p and SIGMA (σ) maps to s.

To handle the problem of ambiguity, Transliterator uses an apostrophe to disambiguate character sequences. Using this procedure, the Greek character PI SIGMA (πσ) maps to p's. In Japanese, whenever an ambiguous sequence in the target script does not result from a single letter, the transform uses an apostrophe to disambiguate it. For example, it uses this procedure to distinguish between man'ichi and manichi.

Note: Some characters in a target script are not normally found outside of certain contexts. For example, the small Japanese "ya" character, as in "kya" (キャ), is not normally found in isolation. To handle such characters, Transliterator uses a tilde. For example, the input "~ya" would produce an isolated small "ya". When transliterating to Greek, the input "a~s" would produce a non-final Greek sigma (ασ) at the end of a word. Likewise, the input "~sa" would produce a final sigma in a non-final position (ςα).

For the general script transforms, a common technique for reversibility is to use extra accents to distinguish between letters that may not be otherwise distinguished. For example, the following shows Greek text that is mapped to fully reversible Latin: