WX notation is a transliteration scheme for representing Indian languages in ASCII. This scheme originated at IIT Kanpur for computational processing of Indian languages, and is widely used among the natural language processing (NLP) community in India. The notation (though unidentified) is used, for example, in a textbook on NLP from IIT Kanpur. The salient features of this transliteration scheme are: Every consonant and every vowel has a single mapping into Roman. Hence it is a prefix code, advantageous from computation point of view. Typically the small case letters are used for un-aspirated consonants and short vowels while the capital case letters are used for aspirated consonants and long vowels. While the retroflexed voiceless and voiced consonants are mapped to 't, T, d and D', the dentals are mapped to 'w, W, x and X'. Hence the name of the scheme "WX", referring to the idiosyncratic mapping.
^Akshar Bharati; Vineet Chaitanya; Rajeev Sangal (1996). "Appendix B". Natural Language Processing: A Paninian Perspective. Prentice-Hall of India. pp. 191–193. ISBN9788120309210. Retrieved 16 February 2014.