Just a quick heads up. The Thai embassy in Vientiane no longer allows applicants to submit visa requests with application forms they downloaded from the embassy’s website.
You must submit a handwritten application form that is provided to you at the embassy and that bears the embassy’s stamp.
They claim to have started this policy two weeks ago. It should be noted, however, that the application forms are still available for download on their website with no warning of a policy change.
TLDR : Answer Summary
The Thai embassy in Vientiane has implemented a new policy requiring applicants to submit a handwritten visa application form provided at the embassy, which should also bear the embassy's stamp. This policy started two weeks ago, despite the application forms still being available for download on the embassy's website.