IIRC there are instances of exceptions of having referral/affiliate link on the OP, I guess that's related of freebitco.in, it was a quality thread and full of info regarding the topic and it wasn't deleted, it was held and even got questioned on meta for discussion. I'm still finding this thread.
It was a niche forum for quite a while (probably until around 2013) Theymos probably noticed this and seemed to play more into a community vibe by allowing almost all of the rules to be broken by users.
Most mods still look at the forum in that way too I think.