I see. But, the way it currently works, if a user forgets the mode, then they receive all results. Considering that there isn't an obvious distinction (from the user's point of view) between handled and unhandled parameters, they're likely to make that mistake. In my eyes, this is the greater of two evils. How about we just keep a list of the "unhandled" parameters we support, mention them in the docs, and if users want more, we can add them in later? It probably wouldn't be a bad idea to vet any unknown parameters before supporting them, anyway.