for those interested
http://www.wikifortio.com/779200/Isaan Lawyers.pdf
Notice: This is a translation of the Police order 777/2551 done by Isaan Lawyers (Isaan Lawyers | Lawyer and attorney | Korat | Khon Kaen | Surin | Buriram | Udon | Ubon). This is not an official translation and it should be used only for information purposes. In case of discrepancy with the Thai version, you should know that the Thai document is the only official one. Red sections are new modifications.
original source : Thai Visa