We need a special page that participants can use to register for an event. This is not part of the wireframes because they assume that the user has JavaScript enabled, hence it all happens when you click the "Register for event" button. However, we do need a special page for the no-JS case, as well as for the (probably very rare) use case when someone wants to join the event without going through the event page. The page would just display a notice about the privacy policy and there would be a button to register; somewhat as minimalistic as this.
Then we also need a page for unregistering. This could be either a separate page, or the same page that you use for registering, but with something different after the slash.
In short, the two options are (actual names TBD; <event_ID> will be the numeric ID of the event):
- Separate pages: Special:RegisterForEvent/<event_ID> and Special:UnregisterForEvent/<event_ID>
- Same page: Special:EditRegistrationForEvent/register/<event_ID> and Special:EditRegistrationForEvent/unregister/<event_ID>