What Nightfox says is 100% correct - and I'd just like to enlarge little bit onto that topic.
We really don't care about your gender, your orientation, or the lack of them
I think we (the organizers) and our attendees are pretty tolerant, but we need to set some standards regarding people's appearance - because if you overstep some limits, people will be offended. When people are offended, that means they don't want to be associated with the offender ... and that is exactly what we do NOT want in a a big social event like EF.
Now, that sounds very abstract, but I want to stress that we're setting these standards not because we're in favour of any kind of gender or orientation. That's also why all our dress code rules are based on outer appearance. None of the other attendees nor the security staff can look into your head. And nobody wants to. Just like nobody wants to make special rules for specially oriented people
So, as a consequence, you're supposed to decide what your role is, and stick to it.
That's where Nightfox argument comes in: If you look like a crossdresser (i.e. like a rather manly guy in womens clothes), you will be asked to wear something appropriate.
We had some rather extreme cases in the pas. I'm
not trying to imply that this example applies to you (I don't know you, after all), but let's just say that a beardy guy with hairy legs in a pink dress will offend people, no matter which gender the person has genetically or psychologically. So we can't tolerate that - since a majority of our attendees wouldn't tolerate it either. It's the way it is. We need to stay on common ground, or else we can't have a harmonic community event.
That's really all there is to it, and all I can say. If you can behave and dress up in a way that's not offensive to a rather tolerant crowd, everything will be fine, and nobody will ask any questions.