D23 has just published the following guidelines for Expo attendees wishing to attend the event in costume/Cosplay: All event attendees — including adults — may attend the D23 Expo in costume dressed as their favorite Disney Character.
Attendees in costume must adhere to the follow guidelines:
(1) Costumes should be family-friendly and may not be obstructive, offensive or violent.
(2) Guests may wear masks. However, masks must not obstruct vision and eyes must be visible at all times.
(3) Guests who dress like Disney Characters may not pretend they are an official Disney Character. Creating lines or collecting money for pictures and/or signed autographs is not permitted.
(4) Costumes should not drag on the ground.
(5) Costumes should not contain sharp objects, pointed objects or materials that may accidentally strike another Guest.
(6) Costumes should not contain any weapons which resemble or could easily be mistaken for an actual weapon. Guests who do not adhere to these guidelines may be refused entry into the event unless his or her costume can be modified to meet the above standards.
The appropriateness of the guest costume will be determined by Disney at its sole discretion.