The following Pokémon do not see much use in the current metagame but can be viable in certain situtations, provided that they are well supported (their sets might not be up to date with the current state of the metagame):

Those Pokémon have never seen much use in the OU tier, but can still be viable in some specific archetypes:

Though the following Pokémon have been Overused in the past, they are not viable in the current metagame. You can still have a look at their sheets (their sets might not be up to date with the current state of the metagame):

The following Pokémon are currently banned from SS OU: