1.    Character Sets

The Tru64 UNIX operating system software supports the Thai Industrial Standard (TIS) character set TIS 620-2533.

The TIS 620 character set is a national standard for a primary set of graphic characters for Thai information interchange. It was first published by the Thai Industrial Standards Institute, Ministry of Industry, Thailand in 1986 (Buddhist year 2529) and was revised in 1990 (Buddhist year 2533). It defines 89 characters.

1.1    Consonants

The TIS 620 character set contains 44 consonants, as shown in the following figure and table:

Figure 1-1: TIS 620-2533 Character Set

1.2    Vowels

The TIS 620 character set contains 18 vowels, divided into four groups.

Five leading vowels; these vowels are placed before consonants:

Six following vowels; these vowels are placed after consonants. The six following vowels are further divided into two groups.

Normal following vowels:

Special following vowels:

Two below vowels; these vowels are placed below consonants:

Five above vowels; these vowels are placed above consonants:

1.3    Tone Marks

The TIS 620 character set contains four tone marks:

1.4    Diacritics

The TIS 620 character set contains five diacritics divided into two groups.

Four above diacritics; these diacritics are placed above initial or final consonants:

One below diacritic; this diacritic is placed below final or clustered consonants:

1.5    Noncomposible Characters

The TIS 620 character set contains 18 noncomposible characters. These characters cannot be composed with above vowels, below vowels, tone marks, above diacritics and below diacritic. Noncomposible characters are divided into four groups.

One no-break space:

Ten Thai digits:

Six Thai special characters:

One word separator:

This character is a nonprintable character. It is used for separating words in Thai sentences. Applications can make use of it to simplify Thai word processing.