Four different keyboard layouts are supported for the Thai input method.
Kedmanee (TIS820-2531) keyboard layout. The Kedmanee layout was designed for the typewriter, not the computer keyboard. The limited number of keys on the typewriter keyboard meant that some of the Thai special characters were not available in the layout. TIS820-2531 has adopted the Kedmanee layout for use with a computer keyboard.
TIS820-2538 keyboard layout. This enhanced Kedmanee layout is an updated version of the TIS820-2531 layout that includes some of the Thai special characters that were unavailable in the original Kedmanee layout. Currently, TIS820-2538 is the only Thai keyboard layout standard that is issued by Thai Industrial Standard Institute.
Pattajoti keyboard layout. The Pattajoti layout was also designed for the typewriter, but with better finger-load distribution.
Configurable keyboard layout. User-defined keyboard layout for the Thai input method.