Just as a refresher, here are some of the rules regarding cosplay and related behavior.
-All props HAVE to be checked (this is copy-and-pasted directly from the website)
All prop weapons brought to the show MUST be approved at the Info Booth as soon as you arrive. We will be looking for the following criteria:
It cannot fire any sort of projectile. (Nerf guns are only allowed if they have been deactivated and cannot fire.)
It cannot be an airsoft weapon. (Yes, even if it’s deactivated.)
It cannot be sharp or pointy enough to cut or pierce someone with moderate pressure. This includes all real swords, daggers and knives. It also includes ceramic blades, needles, syringes and anything that can pierce (for example, a Little Sister syringe made of wood would not be allowed)
-Nudity (again, copy-and-pasted from the website)
[In regard to "booth babes":] Partial nudity, the aggressive display of cleavage and the navel, and shorts/skirts higher than 4” above the knee are not allowed. Cosplayed characters that are playable in-game are an exception to this rule (within reason), and exhibitors must obtain permission from show management prior to the show.
Cosplaying attendees may be asked to alter or modify their costume if it is considered overtly sexual.
-No stilts, remote-controlled vehicles, or skateboards/roller skates
There's seriously not enough room in the convention for this.
-Don't punch, kick, or harass people.
Being in character is fine, but don't actually bother other con-goers. It doesn't matter if you're trying to be the Deadpool-iest Deadpool. Don't do it.
-[Update] There are rules against live steel, but does not include chainmail. Chainmail is allowed! (confirmed by AaronC for PAX East 2016)
I personally have been cosplaying at PAX East since 2014 like a lot of other users here, and can't wait until 2017. Now, what are you planning on cosplaying?