What is the dress code for visiting the Thai Immigration office?

I asked a question about the dress code for a visit to the immigration office. It was a simple and serious question. But was denied because “It’s not a visa advice question “ but on administrative posts when showing the required documentation to visit the office for a visa extension it specifically stated about a dress code. I don’t need to see my post in the main page but either it is a requirement or it isn’t. If it’s a suggestion then suggestest it