RPG has long allowed system-recommendation questions under fairly tight tight rules, and every time they pop up the mods are posting a general comment like the following:
Just a note folks, remember that our sys-rec questions require good subjective basis. You must have played the system within the context of the requirements to recommend it. – Brian Ballsun-Stanton
This seems like a great thing to have in a post notice, with links to the sys-rec tag wiki and the Good Subjective, Bad Subjective blog post.
It would be even cooler if this could be automated...