while trying to apply the Russell Soundex to Jews with Germanic or Slavic surnames (such as Moskowitz vs. Moskovitz or Levine vs. Lewin). D–M Soundex is sometimes referred to as "Jewish Soundex" or "Eastern European Soundex", although the authors discourage the use of those names. The D–M Soundex algorithm can return as many as 32 individual phonetic encodings for a single name. Results of D-M Soundex are returned in an all-numeric format between 100000 and 999999. This algorithm is much more complex than Russell Soundex. As a response to deficiencies in the Soundex algorithm, Lawrence Philips developed the Metaphone algorithm in 1990. Philips developed an improvement to Metaphone in 2000, which he called Double Metaphone. Double Metaphone includes a much larger encoding rule set than its predecessor, handles a subset of non-Latin characters, and returns a primary and a secondary encoding to account for different pronunciations of a single word in English. Philips created Metaphone 3 as a further revision in 2009 to provide a professional version that provides a much higher percentage of correct encodings for English words, non-English words familiar to Americans, and first and last names found in the United States. It also provides settings that allow more exact consonant and internal vowel matching to allow the programmer to focus the precision of matches more closely. See also Match Rating Approach Levenshtein distance References Phonetic algorithms