@Benjamin *****
Hanoi actually says this in regard of a Non b for teaching. It's not a Thai police clearance they may or may not ask for
'
- Police certificate verifying that applicant has no criminal record or equivalents or letter issued by authorised agencies in applicant’s country. (The requirement of the submission of such police certificate is optional. The applicant must submit it if consular officer requests he/she to do so. This requirement is effective as from May 2007)