Crack Den has a plethora of rules (some common sense, but some completely arbitrary.) That you will only be aware of if you have taken part in a specific OOC class, or talked to a specific person. Or happen to have had a divine revelation or a direct connection to the occult. Documenting rules as they are come up with is not just a way to reduce arguments over them, but it also reduces the workload on everyone involved as the admins will need to deal with less of the "Frequently asked questions" and role-players need to do less asking about what they can and can't do.

I've run into some arbitrary kind of rules in my time in CD, which have caused confusion and forced changes in the story writing. Generally, none of which changed the fairness or balance of the situation IC in any way, and were entirely insignificant in the grander scheme of things, but both caused a great deal of unnecessary OOC confusion.

I've seen it suggested that one should check OOC before doing something, but for me this takes the joy of RP out entirely. It almost becomes a matter of running every single post by the other role-players before posting them. Which takes away the sense of anticipation and is logistically impossible in a large scene.

As it is, there's literally no way of knowing whether something that is perfectly normal in real world and gives players no special advantages is allowed or not until you end up doing it in RP and someone takes issue with it, because they happened to be in an OOC class where someone said something. And then you either have to take their word for it or start asking around and wasting everyone's time, and by that point the roleplay has become a secondary matter to figuring out what the rules are.

It's not possible for everyone to make time for the OOC classes, given differing time-zones and work commitments. Having the rules actually documented somewhere is not just a benefit to the players, but the staff as well, both in the form of a reduced workload and in the form of having something official to refer to, rather than. "This person said that person told them that the admins have said two years ago that this is the rule."