Two new tags;
They suppress their contents to any user who doesn't meet their stated requirement, ie: having replied, or having voted, in the current thread.
The person who uses them obviously can see through them, as can admins and mods.
An important caveat on the hide-vote; If you're a smartass who uses it on a thread that has no vote it won't be hidden. Still debating to make it automatically unhide in a closed vote too. Also note this means the delay between posting the post and filling out the poll creation qualifies as "not having a poll", so anyone looking while you're filling it out can see what you were trying to hide, so you might want to consider adding hidden messages after the poll is live, via edit.
[HIDE-REPLY]Congrats, you replied[/HIDE-REPLY]