It might mollify people who disagree with the current implicit policy, and make discussion about the policy easier. Here's one option:

There's a single specific topic that's banned because the moderators consider it a Basilisk. You won't come up with it yourself, don't worry. Posts talking about the topic in too much detail will be deleted. 

One requirement would be that the policy be no more and no less vague than needed for safety.

Discuss.