Consonants follow English and international conventions except where, as in b and f, there is interference from the Japanese-derived vowels. Low-tone-class kh, ng, ch, s, th, f are derived from English Braillek, g, st, s, th, f by adding dot 6. B and low ph are derived from high ph through reflection; p is a superposition of b and ph; the three consonants had been transcribed b, bp, p in Caulfield's day. Letters with asterisks are obsolete. Light cells are high tone-class letters in Thai, medium cells mid tone class, and dark cells low tone class. Consonants of different tone classes have distinct braille letters; complete homonyms, found in Thai only, are distinguished by prefixes. The one prefix in Lao is found in , which corresponds to Thai ying in Braille but corresponds to Thai yak in alphabetic position. Lao corresponds to Thai yak in Braille and looks but corresponds to Thai ying in alphabetic position. In Thai, h is prefixed to low-classnasal stops and non-plosives ng y n m r l w to move them to the high-tone class. Lao has the same system for similar characters ng ny n m l w.
Vowels
The short vowels transcribed a e i o u are taken from Japanese Braille, and the long vowelsā ē ī ō ū are derived from these. ǫ is French and international o, and eu/ue is French œ. The other vowels have little recognizable connection to other braille alphabets. All vowels are written after the consonant in braille, regardless of their order in print. Although the vowels have different forms in print, depending on their environment, they have a single form in braille with few exceptions. *Lao has reassigned to ◌ົ o and moved ◌ຸ u to. When is used in print to indicate a short vowel, is appended to the vowel in braille. ฤๅ and ฦๅ are written as ฤ or ฦ plus า in braille. The one irregularity in Thai, also found in Lao, is for shortǫ, written in braille though not in print as the short variant of –อ long ǭ. Lao has additional, similar regularization of print conventions: for short ເ◌ິ oe, and similarly the braille short sign for a different print diacritic in short ເ◌ຶອ eua and ເ◌ັຍ ia.
Numbers are the same as in other braille alphabets, though dot six is prefixed to the to specify that they're Thai or Lao digits. Thus, a sequence of numbers begins with.
prefix denoting numbers
1
2
3
4
5
6
7
8
9
0
Thai Numerals
๑
๒
๓
๔
๕
๖
๗
๘
๙
๐
Lao Numerals
໑
໒
໓
໔
໕
໖
໗
໘
໙
໐
Braille
Punctuation
Single clause-final punctuation may introduced with, but is otherwise as in English Braille.
.
?
!
;
:
/
There is some variability in the use of the to mark stop/period, comma, and the exclamation point. Thai Braille seems to use for the comma, while Lao Braille uses, unless the latter is a copy error in Unesco.
