Define query string

I'd prefer if we drew a strong-ish line between a web object's location and a web objects metadata. This example appears to include a non-meta data (if I were baking something I'd not want a user-definable bit of meta data to provide me the type, I'd rather someone POST'ed to a specific cake. Quantity is totally legit though.)

In this case we have what *looks like* a GET request (due to the existence of query variables, who POSTs with data in urls anymore?) making a non-idempotent action (baking a cake). I'd much prefer if this was an index route: `http://example.com/cakes?type=chocolate&available_quantity=15` in which case we're providing meta-data to filter the cakes vs telling the machine to bake a chocolate cake.