PLANET_GO_AWAY
… to tell Planet to ignore your post. Feel free to put it in HTML comments, like so:
<!-- PLANET_GO_AWAY -->
Good for extremely personal stuff. But if the feature is working properly, you hopefully won’t be reading this through Planet Xavier anytime soon.
Update: Yes! It finally works! This is to be used sparingly; if you regularly post highly personal stuff, it’s probably safer to go with your blogging service’s “Private” feature, since that’s sure to work even if Planet goes bizzerk for some reason.