Actuall
@Ge**
, what
@Ba***
had originally was an O-A VISA from his country before he came here and he was stamped in for a year when he arrived and when that ran out he would have applied for a year extension based on that O-A VISA entry. AND because it's an O-A visa it requires mandatory insurance AND because his insurance wasn't valid for as long as his previous stamp was he got an extension for the duration of the insurance policy he had.
They usually write on the extension in thai (extended until insurance runs out)