As mentioned in their New User FAQ:
The biggest surprise to new users is our insistence on references in the answers. Many forums will appear to simply accept at face-value the word of a random internet denizen. Here, we expect to be able to independently check what you are saying — that is a key aspect of being a skeptic — as we want to chase down the evidence, rather than relying on authority or personal expertise. You should expect that people will actually follow up and check your references say what you claim they say.
That means anecdotes, personal stories and testimonials are not allowed. Answers that rely on logic need some evidence that the premises/assumptions are valid. Original research is not generally allowed. Ideally, we would like to see links to peer-reviewed empirically-based evidence. This makes writing an answer much harder, but the good answers are appreciated much more.
Should we incorporate a similar policy here, in which answers must provide a Jewish source or get deleted? (Assuming that it's a case where an answer needs a source, as previously defined by the community)?
The topic of whether one shouldn't answer if he or she doesn't have a source has been addressed before. Should we revise that and say that such answers should be posted as comments instead?