Calendar invites have always been the backbone for many guild activities. As WoW has expanded, so has the amount of events for which an calendar invite can be created. We try to provide invites for all of these events so interested parties can do these events with their guild mates instead of finding random people doing them.
However in order to keep us doing these invites, we require bit of politeness from you too. If you do sign up for an event, please be online then and be ready to join for the event. It is always an annoying thing when people who have signed up don't show.
We won't prosecute you if you do fail to come on but we would deeply wish that if something comes up you should try to change your status to declined in the invites. It'll save lot of trouble and make everyone happier.