Inserting and deleting Thai characters changes the display of the text, depending on whether the character classes can be composed.
The following graphics show the sequence of inserting MAIHUNAKAT (AV2 vowel) between SARA_II (AV3 vowel) and YOYAK (consonant) .
MAIHUNAKAT cannot be composed with SARA_II, so it must be displayed in its own cell.
The following example shows the deletion of SARA_II (AV3 vowel).
MAIHUNAKAT can be composed with NONU (consonant class CONS). Therefore, it is displayed in the previous cell.