Tai Dam/Tai Viet

Updated 20 September, 2021

This page gathers basic information about the Tai Viet script and its use for the Tai Dam language. It aims (generally) to provide an overview of the orthography and typographic features, and (specifically) to advise how to write Tai Dam using Unicode.

See also the companion document, Tai Viet character notes, for detailed information about specific Unicode characters.

Phonetic transcriptions on this page should be treated as an approximate guide, only. Many are more phonemic than phonetic, and there may be variations depending on the source of the transcription.

More about using this page
Related pages.
Other script summaries.

Sample (Tai dam)

Select part of this sample text to show a list of characters, with links to more details.
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ꪭꪴꪒ 1 ꪹꪕꪸꪉ ꪀꪱ ꪋꪴ ꫛ ꪎꪲꪉ ꪮꪮꪀ ꪣꪱ ꪻꪠ ꪁꪷ ꪻꪬ ꪼꪒ ꪕꪳ ꪕꪱꪉ ꪀꪾꪚ ꪹꪋꪷꪉ ꪝꪸꪉ ꪕꪮꪥ ꪩꪾ ꫛ ꪶꪔꪙ ꪠꪴ - ꪋꪴ ꪬꪺ ꫛ ꪻꪠ ꪁꪷ ꪻꪬ ꪣꪲ ꪁꪫꪸꪙ ꪎꪱꪉ ꪶꪎꪣ ꪩꪺꪉ ꪹꪥꪸꪒ ꫛ ꪀꪾꪚ ꪹꪥꪸꪒ ꪻꪊ ꪚꪴꪙ ꪀꪾꪚ ꪼꪒ ꪹꪚꪷꪉ ꪒꪲ ꪀꪾꪚ ꪫꪸꪀ ꪭꪰꪀ ꪵꪝꪉ ꪹꪏꪉ ꪹꪭꪙ ꪒꪸꪫ.

ꪭꪴꪒ 2 ꪋꪴ ꫛ ꪻꪠ ꪁꪷ ꪝꪮꪣ ꪼꪒ ꪹꪬꪉ ꪝꪳꪉ ꪁꪫꪸꪙ ꪹꪜꪸꪙ ꪹꪊꪱ ꪀꪾꪚ ꪕꪳ ꪕꪱꪉ ꪹꪏꪉ ꪹꪫꪱ ꪀꪺꪉ ꪻꪚ ꪜꪱꪫ ꪁꪫꪱꪣ ꪙꪲ, ꪹꪚꪱ ꪜꪽ ꪵꪊꪀ ꪹꪋ ꪡꪽ - ꪹꪙ ꪘꪰꪉ - ꪻꪊ ꪈꪾ - ꪁꪫꪱꪣ ꪜꪱꪀ - ꪭꪲꪒ ꪅꪮꪉ - ꪩꪺꪉ ꪜꪴꪙ ꪵꪔꪉ ꪀꪨꪰꪒ ꪄꪮꪉ ꪹꪊꪱ ꪭꪳ ꪫꪱ ꪩꪺꪉ ꪀꪨꪰꪒ ꪮꪳꪙ, ꪶꪀꪀ ꪹꪅꪱ ꪹꪬꪱ ꪭꪱꪀ ꪚꪱꪙ ꪹꪣꪉ ꪬꪱꪀ ꪣꪲ ꪭꪳ ꪫꪱ ꪚꪱꪙ ꪹꪣꪉ ꪙꪾ ꪣꪲꪉ ꪎꪲꪉ ꪄꪮꪉ. ꪄꪮꪉ ꪹꪊꪱ ꪬꪱꪀ ꪼꪒ ꪬꪱꪀ ꪣꪲ ꪭꪳ ꪫꪱ ꪹꪜꪸꪙ ꪵꪔ ꪚꪱꪙ ꪹꪣꪉ ꪕꪰꪒ ꪮꪮꪀ.

Usage & history

The Tai Viet script is used for writing the Tai Dam (Black Tai or Tai Noir), Tai Dón (White Tai or Tai Blanc), Tai Daeng, Thai Song (Lao Song or Lao Song Dam) and Tày Tac languages spoken in Vietnam, Laos, China and Thailand. There is also a diaspora in the United States, Australia and France.

The total population using the three languages, across all countries, is estimated to be 1.3 million (Tai Dam 764,000, Tai Dón 490,000, Thai Song 32,000). The script is still used by the Tai people in Vietnam, and there is a desire to introduce it into formal education there.

ꪼꪕꪒꪾ Tai Dam

Little is known about the origin of the Tai Viet script. It appears to have been derived from the Thai script around the 16th century.

Significant variation occurs in the orthographic conventions of the Tai languages, as well as in their phonologies. A unified, standardized version of the script, with an agreed upon core set of characters, was developed at a UNESCO-sponsored workshop in 2006, and subsequently accepted for encoding in The Unicode Standard.

Sources: Scriptsource, The Unicode Standard.

Basic features

The script is an alphabet. Both consonants and vowels are indicated by letters. See the table to the right for a brief overview of features for the modern Tai Dam orthography.

The Tai Viet script is heavily syllable-based, with exceptions being a very small number of unstressed initial syllables, and loan words.

Tai Viet text runs left to right in horizontal lines.

Words are separated by spaces, although this is a recent innovation.

Each consonant is associated with a high or low class to indicate tone. Tone is indicated by a combination of the consonant class, the syllable type (checked/unchecked), plus any tone mark.

There are no conjuncts or subjoined consonants.

The only syllable-initial cluster involves labialisation, using w.

Syllable-final consonant sounds use a subset of ordinary letters, but since there is no inherent vowel, it is still simple to detect syllable boundaries. Some syllable-final consonant sounds are built into vowel-consonant graphemes.

The Tai Dam orthography has no inherent vowel, and represents vowels using 15 vowel-signs (including 5 prescripts), and 5 consonants. Vowel signs are a mixture of ordinary spacing characters, and combining marks.

There are no independent vowels, and standalone vowel sounds use a vowel-sign attached to [U+AAAE TAI VIET LETTER LOW O] or [U+AAAF TAI VIET LETTER HIGH].

This page lists only 6 composite vowels, made from 6 vowel signs and 3 consonants. Composite vowels can involve up to 3 glyphs, though usually only 2, and glyphs can surround the base consonant(s) on 2 sides.

Tone can be indicated either by diacritics or ordinary spacing characters. Both are a recent innovation. Combining tone marks always follow the root consonant and any combining vowels, ie. they come before any postscript vowel. Spacing tone marks always come at the very end of the syllable.

Character index

Letters

Show

Consonants

ꪝ␣ꪛ␣ꪟ␣ꪕ␣ꪓ␣ꪗ␣ꪁ␣ꪃ␣ꪆ␣ꪮ␣ꪜ␣ꪚ␣ꪞ␣ꪔ␣ꪒ␣ꪖ␣ꪀ␣ꪂ␣ꪇ␣ꪯ␣ꪋ␣ꪍ␣ꪊ␣ꪌ␣ꪡ␣ꪏ␣ꪑ␣ꪅ␣ꪭ␣ꪠ␣ꪪ␣ꪎ␣ꪐ␣ꪄ␣ꪬ␣ꪣ␣ꪙ␣ꪉ␣ꪢ␣ꪘ␣ꪈ␣ꪫ␣ꪧ␣ꪩ␣ꪥ␣ꪦ␣ꪨ␣ꪤ

Vowels

ꪹ␣ꪶ␣ꪵ␣ꪻ␣ꪼ␣ꪱ␣ꪺ␣ꪽ

Tones

ꫀ␣ꫂ

Other

ꫛ␣ꫜ␣ꫝ

Combining marks

Show

Vowels

ꪴ␣ꪰ␣ꪲ␣ꪳ␣ꪷ␣ꪸ␣ꪾ

Tones

꪿␣꫁

Punctuation

Show
꫞␣꫟␣(␣)␣,␣.␣-␣–
Character lists show:

Phonology

These are sounds for the Tai Dam language.

Click on the sounds to reveal locations in this document where they are mentioned.

Phones in a lighter colour are non-native or allophones.

Vowel sounds

Plain vowels

i ɨ ɨ u e o ə ə ɛ ɔ a aː

Diphthongs

ɨə ɨə ɛw wɛ aj am an ap aːw

Consonant sounds

labial dental alveolar post-
alveolar
palatal velar glottal
stop p b t d
      k ɡ ʔ
affricate       t͡ɕ      
fricative f v   s     x h
nasal m   n   ɲ ŋ
approximant w   l   j  
trill/flap     r  

r and ɡ are used in Vietnamese names.

Syllable-final

labial dental alveolar post-
alveolar
palatal velar glottal
stop p t       k ʔ
affricate              
fricative              
nasal m   n     ŋ
approximant w       j  
trill/flap        

Structure

The Tai languages are almost exclusively monosyllabic. A very small number of words have an unstressed initial syllable, and loan words may be polysyllabic.b

The essential character sequence of a Tai Viet syllable is:

prescript vowel?, root consonant(s), combining vowel?, postscript vowel?, final consonant?

The root consonant(s) may be a cluster involving labialisation. Any combining vowel goes after the root consonant(s).

Tone marks expressed as combining characters always follow the root consonant(s) and any combining vowels, which means that they come before any postscript vowel.

Tone marks expressed as spacing characters always come at the very end.

-ap. One other sequence occurs when writing the vowel-final consonant combination -ap, which is written with a vowel placed over the final low-series b, rather than over the initial consonant, eg. ꪁꪚꪾ kp̄aᵐ

The sequence is: root consonant(s) + ꪚꪾ [U+AA9A TAI VIET LETTER LOW BO + U+AABE TAI VIET VOWEL AM]

See gpos, however, for a font variant setting that allows you to store the code points in the normal order, but still display the AM over the BO.

Vowels

Vowel letters

All vowels are written using vowel-signs, eg. ꪁꪲ [U+AA81 TAI VIET LETTER HIGH KO + U+AAB2 TAI VIET VOWEL I] is pronounced ki. Tai Dam uses the following vowel-signs. They may be used on their own, or in combination with others (see composite_vowels).

ꪲ␣ꪳ␣ꪴ␣ꪶ␣ꪵ␣ꪷ␣ꪰ␣ꪱ␣ꪸ␣ꪹ␣ꪺ␣ꪻ␣ꪼ␣ꪾ␣ꪽ

Vowel signs in Tai Viet are a mixture of combining characters and ordinary spacing characters. Several vowel-signs combine vowel+final-consonant, or represent diphthongs.

[U+AAB1 TAI VIET VOWEL AA], [U+AABD TAI VIET VOWEL AN], and [U+AABA TAI VIET VOWEL UA] are normal spacing characters; the rest are combining characters.

Vowel-signs can also be combined to create additional sounds.

Prescript vowel-signs

ꪹ␣ꪶ␣ꪵ␣ꪻ␣ꪼ

Five vowel-signs appear to the left of the onset consonant, eg. ꪶꪁꪙ

Like Lao, Tai Viet uses a visual encoding model, so these characters are not combining characters, and are typed and stored before the base.

Note that [U+AAB5 TAI VIET VOWEL E] should not be typed as two successive [U+AAB9 TAI VIET VOWEL UEA] characters.

Consonants used for vowels

The following characters are also used to create vowel sounds, either alone or as part of a composite vowel.

ꪮ␣ꪯ␣ꪫ␣ꪥ␣ꪚ

[U+AAAE TAI VIET LETTER LOW O] and [U+AAAF TAI VIET LETTER HIGHcan represent vowels on their own. The word ꪮꪮꪀ in fact shows the same character being used as both consonant and vowel in the same word.b

The other three are used in combination with other vowel signs, see composite_vowels.

Composite vowels

Vowels represented by combinations of the above characters:

ꪹ-ꪱ␣ꪹ-ꪸ␣ꪹ-ꪷ␣ꪵ-ꪫ␣ꪵ-ꪫꪥ␣-ꪚꪾ

[U+AAAB TAI VIET LETTER HIGH VO] can be ambiguous in this combination unless there is a tone mark. The sequence ꪵ–ꪫꪥ [U+AAB5 TAI VIET VOWEL E + U+AAAB TAI VIET LETTER HIGH VO + U+AAA5 TAI VIET LETTER HIGH YO] is sometimes used to remove that ambiguity. For details, see medials.

The last item in the list is rather unusual. Some dialects use the combination ꪚꪾ [U+AA9A TAI VIET LETTER LOW BO + U+AABE TAI VIET VOWEL AM] to make -ap,b,7 eg. ꪀꪚꪾ There are 2 possible code point orders that can be used for this: see structure.

Show which combinations contain a given character:
ꪹ-ꪸ␣ꪹ-ꪷ␣ ␣ꪹ-ꪱ
ꪵ-ꪫ
ꪹ-ꪱ
ꪹ-ꪸ
ꪹ-ꪷ
ꪵ-ꪫ
-ꪚꪾ
-ꪚꪾ
Show details about glyph positioning

The following list shows where vowel-signs are positioned around a base consonant to produce vowels, and how many instances of that pattern there are. The figure after the + sign represents combinations of Unicode characters,

  • 5 prescript, eg. ꪶꪁ ok
  • 3 postscript, eg. ꪁꪱ
  • 6 superscript, eg. ꪁꪲ ki
  • 1 subscript, eg. ꪁꪴ ku
  • 2 pre+postscript, eg. ꪹꪁꪱ ɨᵊkā (kaʷ)
  • 2 pre+superscript, eg. ꪹꪁꪱ ɨᵊkā (ke)
  • 1 post+superscript, eg. ꪁꪜꪾ kp̄aᵐ (kap)

Characters that don't appear in the combinations:

ꪲ␣ꪳ␣ꪴ␣ꪶ␣ꪮ␣ꪯ␣ꪰ␣ꪰ␣ ␣ꪻ␣ꪼ␣ꪽ

Standalone vowels

Tai Viet represents standalone vowels using a vowel-sign attached to [U+AAAE TAI VIET LETTER LOW O] or [U+AAAF TAI VIET LETTER HIGH].

Tones

Until the latter part of the 20th century Tai Viet didn't mark tones other than by the consonant class. Since then, however, 2 methods have developed.

Tai Dam speakers in the United States and speakers of the Song language borrowed combining tone marks from Lao/Thai.

꪿␣꫁␣

These tone marks are typed and stored immediately after any combining vowel-sign, if there is one, otherwise after the initial consonant(s).

The Tai community in Vietnam developed an alternative approach, where tone is marked by ordinary spacing characters that are typed and stored after all other elements in the syllable.

ꫀ␣ꫂ

The following chart shows how to tell which tones are associated with a syllable.

Consonant Checked? Tone mark Tone
high checked - 5
open - 4
꪿ or ꫀ 5
꫁ or ꫂ 6
low checked - 2
open - 1
꪿ or ꫀ 2
꫁ or ꫂ 3

Vowel sounds mapped to characters

The following tables show how the above vowel sounds commonly map to characters or sequences of characters.

Plain vowels

i
 

–ꪲ [U+AAB2 TAI VIET VOWEL I], eg. ꪔꪲꪫ .

ɨ
 

–ꪳ [U+AAB3 TAI VIET VOWEL UE], eg. ꪜꪳꪙ .

u
 

–ꪴ [U+AAB4 TAI VIET VOWEL U], eg. ꪄꪴ꪿ꪙ .

e
 

ꪹ–ꪸ [U+AAB9 TAI VIET VOWEL UEA + U+AAB8 TAI VIET VOWEL IA], eg. ꪹꪔꪸꪣ .

o
 

ꪶ– [U+AAB6 TAI VIET VOWEL O], eg. ꪶꪁꪙ .

ə
 
ꪹ–ꪷ [U+AAB9 TAI VIET VOWEL UEA + U+AAB7 TAI VIET MAI KHIT], eg. ꪹꪬꪷꪉ .
ɛ
 
ꪵ– [U+AAB5 TAI VIET VOWEL E], eg. ꪵꪀ꪿ꪙ .
ɔ
 

–ꪷ [U+AAB7 TAI VIET MAI KHIT], eg. ꪝꪷ .

[U+AAAE TAI VIET LETTER LOW O], eg. ꪮꪮꪀ .

[U+AAAF TAI VIET LETTER HIGH O] 

a
 

–ꪰ [U+AAB0 TAI VIET MAI KANG], eg. ꪔꪰꪒ .

 

[U+AAB1 TAI VIET VOWEL AA], eg. ꪮ꪿ꪱꪉ .

Diphthongs and other combinations

 

[U+AAB8 TAI VIET VOWEL IA], eg. ꪣꪸ .

ɨə
 

ꪹ– [U+AAB9 TAI VIET VOWEL UEA], eg. ꪹꪎ .

 

[U+AABA TAI VIET VOWEL UA], eg. ꪎ꫁ꪺꪉ .

ʷɛ
 

ꪵ–ꪫ [U+AAB5 TAI VIET VOWEL E + U+AAAB TAI VIET LETTER HIGH VO]

ꪵ–ꪫꪥ [U+AAB5 TAI VIET VOWEL E + U+AAAB TAI VIET LETTER HIGH VO + U+AAA5 TAI VIET LETTER HIGH YO] in some dialects, to avoid ambiguity, eg. ꪵꪁꪫꪥ .

əw
 

ꪻ– [U+AABB TAI VIET VOWEL AUE], eg. ꪻꪐ꪿ .

aj
 

ꪼ– [U+AABC TAI VIET VOWEL AY], eg. ꪼꪒ꫁ .

aːw
 

ꪹ–ꪱ [U+AAB9 TAI VIET VOWEL UEA + U+AAB1 TAI VIET VOWEL AA], eg. ꪹꪉꪱ .

am
 

–ꪾ [U+AABE TAI VIET VOWEL AM], eg. ꪁꪾ .

an
 

[U+AABD TAI VIET VOWEL AN], eg. ꪜ꫁ꪽ .

ap
 

Consonants

Basic consonants

In the transliteration used here, low class consonants are indicated using an underline.

Stops

high class
ꪝ␣ꪛ␣ꪟ␣ꪕ␣ꪓ␣ꪗ␣ꪁ␣ꪃ␣ꪆ␣ꪮ
low class
ꪜ␣ꪚ␣ꪞ␣ꪔ␣ꪒ␣ꪖ␣ꪀ␣ꪂ␣ꪇ␣ꪯ

Affricates

high class
ꪋ␣ꪍ
low class
ꪊ␣ꪌ

Fricatives

high class
ꪡ␣ꪏ␣ꪑ␣ꪅ␣ꪭ
low class
ꪠ␣ꪪ␣ꪎ␣ꪐ␣ꪄ␣ꪬ

Nasals

high class
ꪣ␣ꪙ␣ꪉ
low class
ꪢ␣ꪘ␣ꪈ

Liquids

high class
ꪫ␣ꪧ␣ꪩ␣ꪥ
low class
ꪦ␣ꪨ␣ꪤ

Other dialects

Three pairs of consonants are used for the Tai Don language, but not for Tai Dam.btd They are:

ꪟ␣ꪞ␣ꪍ␣ꪌ␣ꪃ␣ꪂ

syllable-initial clusters

The consonant wa can appear immediately after the initial consonant in a syllable. It is written using [U+AAAB TAI VIET LETTER HIGH VO].

The pronunciation of a syllable containing WA in non-initial position can be ambiguous, unless there is a diacritic, since the WA may or may not be a final consonant.b Compare ꪀꪲꪫ ḵiw ꪀꪫꪲ ḵwiand ꪵꪀ꫁ꪫ ɛḵ²w (kʷɛ) ꪵꪀꪫ꫁ ɛḵw² (kɛw)

In order to address the latter ambiguity, the character [U+AAA5 TAI VIET LETTER HIGH YO] is sometimes appended to the end of the sequence to indicate the second pronunciation, eg. ꪵꪁꪫꪥ Since j never occurs after ɛ, this can be done without creating a new ambiguity. This spelling is only used in some dialects of the traditional script, however, it has been adopted as a standard in a project sponsored by the Son La Department of Science and Technology.b

The sound kʰʷ exists in Tai Don, but not in Tai Dam. The sound exists in both languages.btd

Syllable-final consonants

Syllable-final plosives are written using the following low class consonants. These create 'checked' syllables.

ꪀ␣ꪚ␣ꪒ

For open syllables ending with nasals or glides, the following high class consonants are used.

ꪣ␣ꪙ␣ꪉ␣ꪥ␣ꪫ

In addition, several vowels carry a final consonant. See vowels. These include:

ꪾ␣ꪽ␣-ꪜꪾ␣ꪹ-ꪱ␣ꪼ␣ꪻ

Consonant clusters

Consonant clusters occur in the following circumstances:

No special characters or viramas are involved, in any of those. There are no conjunct forms or subjoined consonants.

Consonant to script mapping

The following tables show how Tai Dam consonant sounds commonly map to characters or sequences of characters. The sounds are split to show high (h) and low (l) classes, and final consonants (f).

p
h

[U+AA9D TAI VIET LETTER HIGH PO], eg. ꪝꪷ .

 
l

[U+AA9C TAI VIET LETTER LOW PO], eg. ꪜꪳꪙ .

 
l

[U+AA94 TAI VIET LETTER LOW TO], eg. ꪔꪰꪒ .

 
f

–ꪒ [U+AA92 TAI VIET LETTER LOW DO], eg. ꪭꪴꪒ .

 
l

[U+AA92 TAI VIET LETTER LOW DO], eg. ꪼꪒ꫁ .

k
h

[U+AA81 TAI VIET LETTER HIGH KO], eg. ꪁꪾ .

 
l

[U+AA80 TAI VIET LETTER LOW KO], eg. ꪀꪚꪾ .

 
f

–ꪀ [U+AA80 TAI VIET LETTER LOW KO], eg. ꪮꪮꪀ .

 
l

[U+AAAE TAI VIET LETTER LOW O], eg. ꪮ꪿ꪱꪉ .

–ꪀ [U+AA80 TAI VIET LETTER LOW KO], eg. ꪮꪮꪀ .

m
h

[U+AAA3 TAI VIET LETTER HIGH MO], eg. ꪣꪸ .

 
f

–ꪣ [U+AAA3 TAI VIET LETTER HIGH MO], eg. ꪹꪔꪸꪣ .

–ꪾ [U+AABE TAI VIET VOWEL AM in a diphone , eg. ꪁꪾ .

 
f

–ꪙ [U+AA99 TAI VIET LETTER HIGH NO], eg. ꪜꪳꪙ .

–ꪽ [U+AABD TAI VIET VOWEL AN] in a diphone, eg. ꪜ꫁ꪽ .

 
l

[U+AA90 TAI VIET LETTER LOW NYO], eg. ꪻꪐ꪿ .

ŋ
h

[U+AA89 TAI VIET LETTER HIGH NGO], eg. ꪹꪉꪱ .

 
f

–ꪉ [U+AA89 TAI VIET LETTER HIGH NGO], eg. ꪮ꪿ꪱꪉ.

w
h

–ꪫ– [U+AAAB TAI VIET LETTER HIGH VO] (medial), eg. ꪵꪁꪫꪥ.

 
f

–ꪫ [U+AAAB TAI VIET LETTER HIGH VO], eg. ꪔꪲꪫ.

See also the diphthongs ending in w.

 
f

–ꪥ [U+AAA5 TAI VIET LETTER HIGH YO]

See also the diphthongs ending in j.

Symbols

The Tai Viet Unicode block contains no characters with the general property symbol, however it contains 3 letters that act like symbols.

ꫛ␣ꫜ␣ꫝ

The first 2 symbols above are logograms. [U+AADB TAI VIET SYMBOL KON] means person, and is used to distinguish between homophonous wordsb,9 such as ꪶꪁꪙ

[U+AADC TAI VIET SYMBOL NUENG] is a ligature for the word one. b,9  

[U+AADD TAI VIET SYMBOL SAM] indicates repetition of the previous word.

Numbers

There are no native Tai Viet digits. ASCII digits are used.

ꪹꪊꪉ ꪊꪉꪲ ꪠꪱꪒ ꪵꪖꪉ ꪁꪫꪱꪣ ꪼꪕ ꪖꪳ 6 ꪣꪳ 25 ꪁ ꪾ ꪹꪚꪙ 9 ꪜꪲ 2020 Bai thứ 6 mự 25/9/2020
Observation: Examples of dates in Tai Viet. (source)

Text direction

Tai Viet text runs left to right in horizontal lines.

Show default bidi_class properties for characters in the Tai Dam orthography described here.

Glyph shaping & positioning

This section brings together information about the following topics: writing styles; cursive text; context-based shaping; context-based positioning; baselines, line height, etc.; font styles; case & other character transforms.

You can experiment with examples using the Tai Viet character app.

The orthography has no case distinction, and no special transforms are needed to convert between characters.

The script has no context-sensitive shaping, however combining marks do need to be positioned relative to the shape of the base that they are combined with.

Writing styles

Glyph variants. The Tai Heritage Pro font also has font features that allow the following alternative glyph shapes for certain characters.

featurecode point alternative shapes
lcoa [U+AA8A TAI VIET LETTER LOW CO]ꪊ
htoa [U+AA95 TAI VIET LETTER HIGH TO]ꪕ
hpho [U+AA9F TAI VIET LETTER HIGH PHO]ꪟ
auea [U+AABB TAI VIET VOWEL AUE]ꪟ
hoia [U+AADE TAI VIET SYMBOL HO HOI]꫞

Context-based positioning

Contextual positioning. Combining marks need to be positioned relative to the shape of the base that they are combined with. fig_vowp shows an example: the combining marks are higher to the right than the left, because of the size of the glyphs below.

Location of combining marks. The Tai Heritage Pro font offers a variant feature that allows placement of combining vowel signs and tones over the onset consonant, or over the final consonant in a closed syllable, see fig_vowp. The underlying sequence of code points is identical.

ꪕꪳ꪿ꪉ
Font feature vowp as default (left), and set to 2 (right).

Whereas the code point sequence remains the same for the example just shown, the same font feature can also be used to support a different code point sequence for   ꪾ [U+AABE TAI VIET VOWEL AM]. By default, the code point order for the left-hand example in fig_vowp1 would be:

ꪊꪚꪾ [U+AA8A TAI VIET LETTER LOW CO + U+AA9A TAI VIET LETTER LOW BO + U+AABE TAI VIET VOWEL AM]

With the vowp feature set to 1, combining marks appear over the onset, except for this specific combination. This means that you can use the code point sequence:

ꪊꪾꪚ [U+AA8A TAI VIET LETTER LOW CO + U+AABE TAI VIET VOWEL AM + U+AA9A TAI VIET LETTER LOW BO]

ꪁꪾꪉ   ꪊꪾꪚ
With the vowp feature set to 1, combining marks appear over the onset (as shown on the left), except in the sequence AM + LOW VO (right).

Font styles

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Punctuation & inline features

Grapheme boundaries

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Tai Viet has syllables that include free-standing vowel-signs before and/or after the base, eg. ꪹꪉꪱ Tai Viet users do not expect these to be connected to the onset consonant. When a cursor moves across text, they expect it to stop before and after each of these characters, and not skip the complete syllable. All spacing characters behave this way.

Word boundaries

Unlike many other Tai scripts, Tai Viet uses spaces between words.b However, this is a fairly recent innovation.

Brase provides some algorithmic detail for handling older texts without spacing.btd

Phrase & section boundaries

phrase

, [U+002C COMMA]

sentence

. [U+002E FULL STOP]

poems

[U+AADE TAI VIET SYMBOL HO HOI]

  [U+AADF TAI VIET SYMBOL KOI KOI]

Observation: The UDHR text contains regular ASCII punctuation, including commas, periods, and colons, as well as dashes to separate text. Some examples can be seen in the sample text at the start of this page.

1. ꪋꪴ ꫛ ꪝꪮꪣ ꪼꪒ ꪣꪲ ꪁꪫꪸꪙ ꪵꪮꪚ ꪭꪸꪙ - ꪼꪒ ꪹꪤꪸꪒ ꪕꪮꪥ ꪹꪊꪸ ꪶꪒ ꪤꪱꪫ ꪤꪴꪀ ꪹꪚꪱ ꪎꪸ ꪁꪱ ꪙꪮꪥ ꪹꪭꪸꪉ ꪁꪷ ꪼꪒ ꪵꪮꪚ ꪬꪮꪉ ꪋꪽ ꪔꪾꪣ ꪀꪾꪚ ꪤꪱꪫ ꪤꪴꪀ ꪘꪰꪉ ꪶꪠꪉ ꪶꪩ - ꪤꪱꪫ ꪤꪴꪀ ꪋꪽ ꪔꪾꪣ ꪭꪳ ꪵꪣꪙ ꪄꪮꪉ ꪄꪰꪒ ꪹꪭꪸꪉ, ꪤꪱꪫ ꪥꪴꪀ ꪀꪲ ꪗꪺꪒ ꪀꪾꪚ ꪝꪳꪉ ꪹꪉꪸ ꪭꪳ ꪹꪜꪸꪙ ꪼꪄ ꪀꪫꪱꪉ ꪀꪾꪚ ꪤꪱꪫ ꪥꪴꪀ ꪋꪽ ꪎꪴꪉ ( ꪀꪱꪫ ꪭꪮꪀ ) ꪹꪜꪸꪙ ꪕꪮꪥ ꪈꪫꪸꪙ ꪔꪰꪀ ꪹꪋꪷꪉ ꪝꪸꪉ ꪻꪬ ꪹꪚꪱ ꪁꪫꪱꪙ ꫛ ꪻꪒ ꪵꪮꪚ ꪼꪒ.

Observation: Example ASCII punctuation in UDHR. (source)

Poems & songs. The only punctuation in the Unicode Tai Viet block is for poems and songs: [U+AADE TAI VIET SYMBOL HO HOI] marks the beginning and [U+AADF TAI VIET SYMBOL KOI KOI] marks the end of the text.

Parentheses & brackets

  start end
standard

( [U+0028 LEFT PARENTHESIS]

) [U+0029 RIGHT PARENTHESIS]

ꪉꪮꪙ ꪶꪕ ꪋꪴ ꪹꪋ ꫄ꪤꪙ ꪹꪣꪉ ꪀꪰꪚ ꪀꪺꪀ ꪶꪭꪥ (Ngon tô chu chựa dần mương cắp Quốc hội)
Observation: Examples of parentheses in Tai Viet. (source)

Quotations

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Emphasis

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Abbreviation, ellipsis & repetition

Repetition. [U+AADD TAI VIET SYMBOL SAM] indicates repetition of the previous word.

Inline notes & annotations

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Other inline ranges

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Other punctuation

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ꪉꪮꪙ ꪶꪕ ꪖꪳ 2 ꪣꪳ 05 ꪁꪾ ꪹꪚꪙ 8 ꪜꪲ 2019 – ꪁꪱꪫꪣ ꪶꪕ ꪵꪔ ꪶꪡꪉ ꪚꪱꪙ ꪙꪱ
Observation: Example of en-dash in Tai Viet. (source)

Line & paragraph layout

Line breaking & hyphenation

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Observation: The primary break point for text seen online is the inter-word space.

Show (default) line-breaking properties for characters in the Tai Dam orthography.

Text alignment & justification

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Letter spacing

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Counters, lists, etc.

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Styling initials

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Page & book layout

This section is for any features that are specific to Tai Viet and that relate to the following topics: general page layout & progression; grids & tables; notes, footnotes, etc; forms & user interaction; page numbering, running headers, etc.

Languages using the Tai Viet script

According to ScriptSource, the Tai Viet script is used for the following languages:

Online resources

  1. Universal Declaration of Human Rights - Tai Dam
  2. Voice of Vietnam 4

References