The Pronunciation Lexicon Specification (PLS) is about  How to pronounce words and phrases, How to deal with the variability of pronunciations by country, region, person, etc, How to spell abbreviations and acronyms. The Pronunciation Lexicon Specification is a W3C Recommendation, which is designed to enable interoperable specification of pronunciation information for both speech recognition and speech synthesis engines within voice browsing applications. Based on this standard below Pronunciation Lexicons have been developed.