Well, think of Siberia is a place of exile to which people are sent, and from which they may reasonably expect to return once they are penitent and cold and lonely... whilst the Oubliette is a musty forgotten archive for those threads that no one... no one wants to remember ever existed.
We don't delete threads much. Just spam. As you lot tend toward the upper echelons of the silly, the depraved, and the just plain weird we like to have a storage place for oddities that maybe never should have seen the light of day. Tread carefully in the Oubliette. There be dragons.
On a good day we have chickens and can read the signs in the entrails. Sometimes we toss a coin. Some days are opposite days and we just do stuff to be contrary... or it might be a full moon.
Siberia isn't intended for no-hoper threads as much as it is a place for hopeless posters exiled from the loving bosom of community... who in their time there may initiate no-hoper threads. Or works of pure demented genius. Usually an Oubliette thread is defunct... inactive - or it might be moved here at its inception.; a symbolic act of abortion. In later days infanticide. Call it post eugenics. Not that we want to remove anyone's freedom to breed. We just want to hide the defects in the closet
It really couldn't get simpler or more self-explanatory, really... now could it?
Siberia is entirely appropriate for threads of political subversion. The Empire wishes to have all reckless free thinkers in an orderly place for observation and possible annihilation self-select for a little holiday - where they may exercise their dangerous liberating ideas without threat of ever being heard fear of penalty or harm.
On the other hand...the Oubliette grows nice dust bunnies. Do not disturb. We are among dead here. No one will hear you scream.
Except of course the dragons on level eight, and they're a mite hungry right now.
So, in other words, the Oubliette is for threads that have been closed for various reasons but can still be viewed. We don't delete threads in the same way Librarians don't burn books.
Siberia is for threads that are not necessarily in need of closing but do need a time out. They need to chill. Its humorous to have a thread discussing penalties in our subforum devoted to threads that are bordering on penalty infractions.*
Finally, we have the Crime and Punishment area devoted to actual crimes or infractions.
Can you make threads in the Oubliette and Siberia? Yes. Should you? Probably not.