Police Order 548/2562.
Effective 31 Oct 2019.
Subject:
Health insurance for Non Immigrant O-A visa
Extension of Stay following this Non Imigrant O-A visa
Using this visa at entry inside Thailand.
It is discussed over and over again on this page, but with most of the reports people start the same discussions again and again.
It seems some computers do have more functions than others, so not all of you are able to read the Police order at their website:
[members only]
It also seems not very easy to download the complete version starting with the Thai text on website:
[members only]
For your information, the in English translated pages.