The bar/club you are going probably has some sort of basic protocol that they have posted on their website.
Usually, if it is Jocks Night Only, they will want all the people who enter after a specific time to be wearing jocks only (or be fully naked?). They also may want to insist that you may wear only flip-flops or only white/black sneakers.
They may also want to ban flashing any phone lights, etc., perfumes, etc.
So, it only makes sense to go their web page and see what is it that they claim is their protocol for the night, and show up accordingly.
Do not take any valuables with you. Make sure that they provide condoms and lube and/or take some with you.
Be prepared that some clubs tend to be too picky over their protocols. Rules are fine in my books, but hairsplitting ain't.
I was wearing a light black leather aviator jacket with no fur inset or anything at one of the regular nights at one of the popular SoMa clubs, only to be told at the gate that they only wanted the folks to have one layer of clothes on them? Sure, more power to them.
I just walked over to the next club where the guys at the gate were happy to see me, and give me a free entrance, too. So, respect the rules, but do not let them go over the top either.