Slightly better than a purely miscellaneous word list is a pair of otherwise valid noun phrases connected by a preposition that's commonly used in command phrases. This will match commands where the user has assumed a command with a prepositional structure that doesn't exist among the defined commands. Since we have badness, we'll be ignored any time there's a valid command syntax with the same prepositional structure.

grammar completeNounPhrase(miscPrep) :   NounPhraseProd