If you use the Royal Thai Consulate General in Georgetown to apply for your TR come equipped with a copy from your malaysian entry stamp in your passport. If you forget they send you out to a man in a van outside the building charging you 10RM for it.
TLDR : Answer Summary
When applying for a TR visa at the Royal Thai Consulate General in Georgetown, it's important to bring a copy of your Malaysian entry stamp in your passport. If you forget this document, you will be directed to an external service charging 10RM to obtain a copy.