1) It would be nice if everyone gave his or her ships extra festive lights
2) It's a wedding so act like it... no "nonsense" messages during the ceremony.
3) Preferably everything said in local chat, by the participants, should be RP about the event.
Rules:
1) Yes there will be people hostile to you in this event. But keep your finger of the trigger.
2) Stick to the guidelines and have a nice and friendly event.
And to give you an idea how the couple will be dressed: