Item
    kind Text
    normKind Text
    bought Day Maybe
    expires Day Maybe
    opened Day Maybe
    Foreign Kind fkType normKind
    deriving Show Eq
Reference
    normKind Text
    kind Text
    UniqueRefKind normKind
    Foreign Kind fkType normKind
    deriving Show Eq Ord
Kind
    normKind Text
    type Text
    Primary normKind
    UniqueKind normKind
    deriving Show Eq