Thai Industrial Standard 620-2533, commonly referred to as TIS-620, is the most common character set and character encoding for the Thai language. The standard is published by the Thai Industrial Standards Institute (TISI), an organ of the Ministry of Industry under the Royal Thai Government, and is the sole official standard for encoding Thai in Thailand. The descriptive name of the standard is "Standard for Thai Character Codes for Computers" (Thai: รหัสสำหรับอักขระไทยที่ใช้กับคอมพิวเตอร์). "2533" refers to year 2533 of the Buddhist Era (1990), the year the present version of the standard was published; a previous revision, TIS 620-2529 (1986), is now obsolete.
TIS-620 is the IANA preferred charset name for TIS-620, and that charset name is used also for ISO/IEC 8859-11 (which adds a no-break space character at 0xA0, which is unassigned in TIS-620). When the IANA name is used the codes are supplemented with the C0 and C1 control codes from ISO/IEC 6429.