noosard wrote: ↑June 13, 2020, 8:33 pm
So you need at least a dead visa for your permission of stay
No.
If you have a single entry visa, it will be "dead" (for want of a better word) when you enter Thailand, and get your "permission to stay" according to the terms of the visa (generally). This could be 350 (or whatever) days before the visa expiry date, or may be 1 day before. If you want to leave and come back within the term of that permission, you need a re-entry permit.
If you want to stay a further period (say 12 months) you need to apply, and qualify for, an extension of your permission to stay (not your visa).
If you have a multi entry visa, it will not be "dead" until the expiry date. And you can come and go as often as you like before the expiry date, and will be given permission to stay each time according to the terms of the visa (generally 12 months). And if that permission runs into a period after the expiry date, you will need a re-entry permit to keep that permission alive.
What woody is saying is not pedantic - it is correct. It is when terms/expressions are carelessly thrown about that confusion reigns.