As @DaBull007 has stated, you can use the stock code forum specific to the stock you are thinking of or currently shorting.
Being that you are going against what most are hoping to achieve (you actually want to see the stock fall), make sure you have a decent post with facts or else reasons to plead your case as to why you are shorting the stock/believe the stock is about to fall.
Make sure you are thick skinned, cause you will surely get the optimistic stock holders and followers to try and discredit your analyst. Keep the post(s)/reply(s) civil with no baits/flames/attacks towards members that are trying to shut you down, discredit your analyst. It is better to report those posts aimed towards you that go against the HC rules, rather than taking the law (so to speak) in your own hands. You and any others that go against the rules will probably be moderated or else temp suspended.
Also, I think in general shorting with no specific stock, a discussion on the short term trading forum might also be a good idea.