Is there such thing as private threads or is that just a myth?

myth

https://dollars-bbs.org/random/src/1519283121123.png

There's a very low chance a hidden board would appeared under the random board button, here's a screenshot. I've seen it 3 times until now and haven't had the chance to see it again. When you click it, it directs you to the password page with the 'password' changed into 'ticket code' for a brief second and then closes your browser. Has any of you seen it?

>>3 What the hell, that sounds badass.

>>4 Keep on a look out