I am connoisseur, because a common recipient, of the unvite, the invitation made for purely formal reasons but which is never meant to be taken. It comes in many varieties.
There is the invitation to a party when the inviter knows for certain that you have a prior engagement or are going to be out of town. This is the province of the amateur.
The better variety is the invitation that comes just a little too late, say just the day before the event. Of course, this variety leaves open the possibility that the invitee might actually attend, but it is just this that makes this unvite a classier variety than the invitation that arrives after the event has already occurred or begun.
There is a hybrid—the work phone or work email unvite—in which the invitation is made via a message that won't be retrieved until after event though, for the honor of the inviter, the invitation was technically made before the event.
Another flavor is the misdirected invitation, sent to the wrong address, to the wrong voicemail, to the wrong email and its cousin, the "I told N. to invite you, didn't she?"
But perhaps my favorite is the invitation that gets to the invitee—or unvitee—with just enough time to plan to attend but not quite enough information. The time is missing, the address is incomplete or it's assumed that you know where it is when clearly you don't, it's unclear what sort of event exactly it is or what you're supposed to bring or whether you can bring a guest and everything is just unclear enough that you feel uncomfortable asking and so are guaranteed not to show.
This is probably the most masterful move. The invitee won't come, the invitation was made and the inviter will later get the social upper hand in expressing how much he was missed or asking why he didn't come.