INCOMPLETE - WORK IN PROGRESS It is common for those learning Thai to run across transcription of spoken Thai into systems other than the Thai script. At first, one would think that there would be a single correct transcription, for example based on the International Phonetical Association (IPA) that would accurately capture all the sounds in Thai. One would be wrong. There are a large number of transcription/transliteration systems, each with their own history and rationale. Understanding more about them is useful to Intermediate Thai language learners. Normally a beginning learner is simply at the mercy of whatever Thai language books/material and/or Thai teacher/tutor is most convenient or chosen for the learner. As for the author of this essay, I held a bias against the IPA system as I wondered why I had to learn a third system in order to learn the second system (Thai). It turns out I was incorrect and it would have been better to learn not only the phonemes and phonology of Thai, but also that of English. A better understanding of both is the key to cutting through the confusion of Thai transcription systems that proliferate. Topics to follow: - Transcription system goals - Script-to-script - Sound-to-script - Reversibility - Sound-to-sound - ASCII/En keyboard transcription - Transcription systems - True (full) IPA - Hybrid systems - AUA -