Comment 10 for bug 131165

To follow on from Robert's idea of the referrer, you could use a referrer page whose URL contains the eventual destination and the notification information. So the submission of the post request would redirect you to say /+notification/?message=thanks+for+the+bug&destination=/bugs/12345. This would then redirect you to /bugs/12345, which could look at the referer to see it should display a notification. If someone copy&pastes or bookmarks the page it will not be shown.

If they are using privacy software that hides the Referer (even for the same site and on ssl, which would be extreme) it will still work, but they won't get the notification. (This case is probably moot because such software would typically block cookies too.)