User:RichardW57/Precise System of Transliteration of Thai

The Precise System of Transliteration of Thai was introduced in 1939 as a fuller version of the Royal Thai General System of Transcription (RTGS). Whereas the RTGS does not show tones or vowel length, the Precise System is intended to show tones and indicate unpronounced letters. It is therefore a combined transcription and transliteration.

Features

 * Each syllable is transliterated independently . 'Syllable' means phonetic syllable.
 * Dormant and unpronounced letters are written in brackets.
 * Transliteration of consonants in initial position reflects both the letter with which they are written in Thai and its pronunciation.
 * Consonants in final position are transcribed, with the spelling indicated in parentheses or shown by a simple diacritic.
 * Syllable-final glottal stop is transcribed if and only if it is written by ะ, in which case it is written as ḥ. This is shown in the vowel table below.
 * Complex, multi-element vowel symbols are transcribed and transliterated as a unit, and are recorded relative to consonants in their phonetic position.
 * Implicit vowels, including anaptyctic vowels, are recorded.

Systematic Use of Diacritics and Secondary Elements of Digraphs

 * Shortness of vowels is indicated by breve over the vowels.
 * Tone is indicated by a tilde or a grave, circumflex or acute accent above the vowel. If the vowel has a breve, this mark goes above it.
 * Letters that represent retroflex consonants in Pali and Sanskrit are indicated by a dot below.
 * A dot below can also indicate the first element of the transliteration of what correspond to the Sanskrit vocalic consonants (ฤ ฦ).
 * Aspiration is indicated by suffixing one or both of  and a spacing rough breathing.  marks Pali/Sanskrit aspirated stops, namely ข ฆ ฉ ฌ ฐ ฒ ถ ธ ผ ภ.  The spacing rough breathing marks Pali/Sanskrit voiced oral stops, namely ค ฆ ช ฌ ฑ ฒ ท ธ พ ภ.  Both categories represent aspirated consonants in Thai.
 * Primes are used to distinguish consonants that sound the same.

Non-Systematic Use of Diacritics

 * The letter <ç> represents ซ, and not ศ as in some Sanskrit transliterations.
 * The rarer vowel ใ is distinguished from ไ by transliterating the former as <ăĭ> and the latter as <ăi>.

Implementation Notes

 * Apart from aspiration, consonants are primarily based on English.
 * Two styles of spacing rough breathing are in use - <ʽ> (Unicode designation U+02BD MODIFIER LETTER REVERSED COMMA) and <ʿ> (Unicode designation U+02BF MODIFIER LETTER HALF RING).

Ambiguities and Other Issues
''Warninɡː the assessments here are currently oriɡinal research, and will ultimately need to be moved elsewhere or backed up by citations.

Editors: If you delete this, please move to talk.''

It is not clear from whether tones should always be marked. In the first two groups of words transliterated, tones are not marked:
 * Tone-Marking

Now, it may be relevant that there are no tone marks and the tone rules work smoothly. Alternatively, given the discrepancy in the transliteration of ราชบุรี, the examples may simple be inept.

In the second group, which is intended to demonstrate the use of a 'hyphen' to show syllable divisions, tones are mostly marked.

Is this sʹ as in the table or ś as in the example and in IAST? Griswold uses ś in his examples.
 * Transliteration of ศ

Both สุด and สุต transliterate to sŭ̃tǃ
 * Simple Irreversibility

It is not clear how these are to be transliterated. Griswold offers two examplesː
 * Double Acting Consonants

nă̂kʽǫn(r) ś(r)í thʽă(rr)mmâràt(cʽ) for นครศรีธรรมราช ẵyŭ̂t(thʽ)ă̂ya for อยุธยา

The first method is not invertible, for consider krŏmmă̂hãttʽăiy for กรมมหาดไทย and krŏmmă̂tʽà for กรมท่า. In the first case, Thai has double ม, while in the second case, there is only a sinɡle ม.

The second case is contrary to the principle of transliterating syllable by syllable, but would work in most cases.

A further literature search is needed to determine if this issue has been resolved.

This appears to be a valid interpretation. The combination –อร does not occur in Thai with the transliteration ǫn(r), so the combination is invertible.
 * –ร ǫn(r)

Recovering เสน่ห์ from sẵnẽ(h) takes some ɡymnastics. Can it be done by a reliable alɡorithm?
 * Consonant Governance and Tone Mark Recovery

Criticism
Explain negligible usage

Transliteration table
For consonants, the transcription is different depending on the location in the syllable. In the section on vowels, a dash ("–") indicates the relative position of the initial consonant belonging to the vowel.

Because of the original relationship with the RTGS, the 1939 RTGS transliterations are also shown except for final consonants. Since then, the RTGS has dropped some distinctions but has not introduced any new distinctions.

Allowed Variations
The following substitutions are allowed: