Visually, it should be somewhat inline with the ad that @IlmariKaronen created. That way, our site-related "ads" adher to some kind of (let's just call it) corporate identity.
Hmm, I just realized that our help center doesn't seem to actually say that reference requests are off-topic, even though it's one of the canned close reasons. :/
We should probably fix that.
(Where "we" really means the ♦ mods, since I believe they're the ones who can actually edit that page.)