I once played a game called MAD. Or possibly M*A*D. It consisted of a library of stories, which were marked up so that when parsed the user was asked for words. The output could be quite amusing...

Enter a name: Julie
Enter an adjective: bouncy
Enter a noun: ball
Enter a verb: throw
Enter a name: Michael

Julie yelled "Throw me that bouncy ball, Michael!"

A BlankFill has a type (adj, verb, adverb, noun &c). It can be slotted into a FillPhrase.

— AlexisLi? - 07 Dec 2001