3.8 — Thai Script

Romanization of Thai Script

Thai script will be transcribed following the → Royal Thai General System of Transcription, which is the only generally accepted rule for transcription. Unfortunately, this system is not widely adopted, and even when it is, it is often not adopted consistently. Therefore, spelling or transcription variants are frequently published, which are not based on a rule other than individual, native-language adaptations of the pronunciation of Thai words, and can only lead to confusion. 

An example of a widely used transcription variant is the Thai word for bamboo (ไผ่), which is correctly transcribed "phai", and not "pai". The → digraph "ph" in words transcribed from Thai indicates an aspirated "p" (and represents the sound of "p" like the name Paul), whereas the digraph "ph" in English words usually derives from Greek φ (and represents the sound of "f" like the word photograph). 

For all Thai geographical names, Thai plant names, and other words in Thai script, the Royal Thai General System of Transcription will be strictly adopted. For Thai personal names, the same system applies, except if it is known that a certain person uses his or her own constant way of Romanization, then this will be followed. 

The International Organization for Standardization (ISO) offers transliteration rules for Thai script (ISO 11940), published in 1998, updated in 2003, and confirmed in 2008, which are virtually not in use except by linguists.