Here you will find the polymorphic values which represent all of the interfaces that a given module can fulfill. You can tell which module a given polymorphic value represents by removing the first and last underscores, and replacing all other underscores with dots. For example, _Data_ByteString_ represents the Data.ByteString module.

If you'd like to add a new instance for a given interface, then you must import that module's corresponding typeclass (those are not exported here).