These functions apply a phonetic transformation to input.

METAPHONE is used to index words by sound. (also be called META1).

PREFIXMAP (also called META2) uses a truncation mapping such that for each token, the truncation function outputs the first three characters. If the token is less than three characters, the entire token is output.

IDENTAPHONE (also called META3) uses an IBM® proprietary phonetic algorithm.

ARABPHONE (also called META4) is used to apply phonetics to the English translation of Arabic names. (This function does not work on Arabic character sets; see ARABICPHONE).