I'd take a code of conduct before the dress code. Though, appropriately enough, I suppose the latter signals the former
There's been pressure on the D Language Foundation to have a CoC. I've consistently refused one. The only thing I demand is "professional conduct". Sometimes people ask me what professional conduct is. I reply with:
1. ask your mother
2. failing that, I recommend Emily Post's book on Business Etiquette.
And an amazing thing happened. Everyone in the D forums behaves professionally. Every once in a while someone new will test this, their posts get deleted, and then they leave or behave professionally.
What? Why? Are you really that bothered by other people wearing stuff that you wouldn't personally want to wear? I can't even imagine going through life with strong feelings about how other people should dress; it legitimately sounds exhausting.
When I'd pick up my date, and she had obviously spent a lot of time on her appearance, it'd make me feel like a million bucks.