textworld_data/dnd/logic/clue.twl

type clue : t {
    predicates {
        discovered(clue);
    }

    inform7 {
        type {
            kind :: "clue-like";
            definition :: "clue-like is a kind of thing. clue-like is privately-named.";
        }

        predicates {
            discovered(clue) :: "";
        }
    }
}