Tai Viet ꪎꪳ ꪼꪕ
Script type	Abugida
Period	16th century-present[1]
Direction	Left-to-right
Languages	Tai Dam,Tai Daeng,Tai Dón,Thai Song andTày Tac
Related scripts
Parent systems	Proto-Sinaitic alphabet Phoenician alphabet Aramaic alphabet Brāhmī Tamil-Brahmi Pallava Old Khmer Sukhothai Thai Tai Viet
ISO 15924
ISO 15924	Tavt(359), ​Tai Viet
Unicode
Unicode alias	Tai Viet
Unicode range	U+AA80–U+AADF

TheTai Viet script (Tai Dam:ꪎꪳ ꪼꪕ ("Tai script"),Vietnamese:Chữ Thái Việt,Thai:อักษรไทดำ,RTGS: akson taidam) is aBrahmic script used by theTai Dam people and various otherThai people inVietnam andThailand.^[2]

According to Thai authors, thewriting system is probably derived from the old Thai writing of the kingdom ofSukhotai.^[3] It has been suggested that theFakkham script is the source of the Tai Don, Tai Dam and Tai Daeng writing systems found inJinping (China), northern Laos, andVietnam.^[4]

Differences inphonology of the various local Tai languages, the isolation of communities and the fact that the written language has traditionally been passed down from father to son have led to many local variants. In an attempt to reverse this development and establish a standardized system,Vietnam's various Tai people in the formerNorthwestern Autonomous Region were approached with a proposal that they should agree on a common standard. Together with Vietnamese researchers, a first proposal calledThống Nhất (or Unified Alphabet) was developed, which was published in 1961 and revised in 1966.^[5][6] A unified and standardized version of the script was developed at a UNESCO-sponsored workshop in 2006, named "chữ Thái Việt Nam" (or Vietnamese Tai script). This standardized version was then approved to be included in Unicode.^[1]

From May 2008, the improved Thai script was put into official use.^{[clarification needed]}

The script consists of 31 consonants and 14 vowels.^[3] Unlike most other abugidas or brahmic scripts, the consonants do not have an inherent vowel, and every vowel must be specified with a vowel marker. Vowels are marked with diacritic vowel markers that can appear above, below or to the left and/or right of the consonant.^[1] Some vowels carry an inherent final consonant, such as/-aj/,/-am/,/-an/ and/-əw/.^[7]

The script uses Latin scriptpunctuation, and also includes five special characters, one to indicate a person, one for the number "one", one to repeat the previous word, one to mark the beginning of a text and one to mark the end of a text.^[7]

Traditionally, the script did not use any spacing between words as they were written in a continuous flow, but spacing has become common since the 1980s.^[7]

Initial consonant letters have both high and low forms, which are used to indicate tones. The high consonants are used for the syllable final letters -w, -y, -m, -n and -ng. The low consonant letter -k is used for final/k/- and/ʔ/-sounds, while low consonant letters -b and -d are used for final/p/ and/t/.^[8][7]

The consonant character's position is marked with a circle: ◌.

• When/ɔ/ has a final,◌ꪮ is used instead.

Some additional vowels are written with a combination of two vowel characters. The following four combinations are used for Tai Dam:

Some sounds are spelled differently inTai Dón compared to in Tai Dam:^[10]

Traditionally the script used no tone marks and only partially indicated tones with the high/low consonant differentiation. The reader had to guess the tone and thus meaning of a word from context. In the 1970s two tone marks were developed, called mai nueng and mai song.^[1] Tone 1 is marked with only a low consonant. Tone 4 is marked with only a high consonant. Tone 2 is marked with the first tone mark and a low consonant form. Tone 5 is marked with the first tone mark and a high consonant form. Tone 3 is marked with the second tone mark and a low consonant form. Tone 6 is marked with the second tone mark and a high consonant form.^[8][7]

Proposals to encode Tai Viet script inUnicode go back to 2006.^[11]A Unicode subcommittee reviewed a February 6, 2007 proposal submitted by James Brase ofSIL International for what was then called Tay Viet script.^[12]At the ISO/IEC JTC1/SC2/WG2 meeting on April 24, 2007, a revised proposal^[7] for the script, now known as Tai Viet, was accepted "as is", with support^[13] from TCVN, the Vietnam Quality & Standards Centre.

Tai Viet was added to the Unicode Standard in October, 2009 with the release of version 5.2.

The Unicode block for Tai Viet is U+AA80–U+AADF:

• Miyake, Marc. 2014.D-ou-b-led letters in Tai Viet.

• SIL Tai Heritage Pro Font Download
• Proposal to encode additional Tai Viet characters for the Jinping Dai

• Brahmic scripts
• Writing systems of Asia
• Tai languages
• Writing systems introduced in the 16th century
• Languages of Vietnam
• Vietnamese inventions
• 16th-century establishments in Vietnam

• Webarchive template wayback links
• Articles with short description
• Short description matches Wikidata
• Scripts with ISO 15924 four-letter codes
• Articles containing Vietnamese-language text
• Articles containing Thai-language text
• Wikipedia articles needing clarification from July 2020
• Pages with plain IPA