I didn't actually end up attending black and white ball because my feet were killing me by the time we were about ready to go to it, but I think that more at-con information would be better.
It was very difficult to find information in the little pocket guide that we used to get around; all we saw was a little blurb about it, nothing about when and where. Any blurbs need that basic information, and in the case of B&W ball, a comment on the dress code and that it is strictly enforced. You don't have to enumerate the rules of the dress code in the pocket guide, but definitely where to find it (both online and in the big program).
I don't know what it was like at the door since I didn't actually make it out there, but it seems like a sign that specifically states the rules that you could point to if you can't let somebody in would be helpful. I'm hearing these stories about "not x brand of dance shoes," which is clearly a miscommunication. If the rules are nickel diameter heels no more than 4" high, then that should be what is pointed to. It's not going to help much with getting the word out before hand, but at the very least it would help with consistency in enforcement.
Regarding getting word out before hand; definitely take advantage of social media. The only mention of it on facebook was from Day 3, which is too late for people to make sure their shoes are correct. Similar twitter, maybe utilize a hastag #FanimeB&WDressCode or something similar. More a critique of the website than anything else, but I feel that the links could be made clearer (underlining maybe?). For something as important as the dress code for this event, the link to it needs to be obvious. Relying on scrollover changes doesn't help if you don't know to scroll over, and the font choice was bold enough in general that listing the links in actual bold didn't make it obvious there was something special there unless you looked closely. People skim, I know I do, and if you want to get information out, you need to make sure getting to that information is unmistakeable.