There are some other strange laws in Thailand but this seemed to be the most "interesting" one to me. How are they even going to find out? Are they going to observe your bulge?
There are a lot of sources you can find where this law is mentioned:
- Weirdest Laws in Thailand, Why Go?
It’s against the law to leave your house in Thailand if you’re not wearing underwear.
- A traveller's guide to Thailand's laws, World Nomads
Strange Thailand Law #1: The Underwear Law
Hey, who are we to judge, but technically it is illegal to leave your house in Thailand if you are not wearing underwear.
- Strange laws that could land you in trouble in Thailand, One Step 4ward
It’s illegal to leave the house without your underwear on.
It is even asked in Quora but there aren't any details about the official law in the answer given; on the other hand, the user talks about his experience: Is not wearing underwear illegal in Thailand?, Quora
(Maybe, the law pertains to the citizens only.)
Is this true? Is it possible to find the official law?