For more information and registration, look here:
This is an external event and needs registration on external websites. If you RSVP here on our group page, it's not valid as an event registration and will not grant you access to the event.
By RSVPing here, you just give indication to other group members about your planning to participate. This might help you to find potential hack team members, share ideas etc.
So, it's intended as an additional planning and socialising tool! ;-