I'm sorry for the spoiler:
This is my example for 4-2. The 2nd checkbox won't activate
So the QUIVBAB is a part of the compound puzzle, the out-of-level bonus unlocking thing.
The INPUT is usually an existing word to make the game significantly more realistic to beat. E.g. it would be a “DAGGER” instead of “DGRYYR”. The bonus-related unlocks are different as they may involve gibberish. They’re the ultimate challenge and they involve multi-level deciphering (and they unlock bonus levels after that!)
So even if the OUTPUT matches something, what you need to do is to find a correct INPUT, the decoded keyword.