inheritable

Whether this declaration may be a component default. false by default.

An inheritable declaration is also left out, instead of refused, under a parent whose protocol refuses it, whether a component default provides it or a component declares it directly.

An inheritable declaration is not additive: one that is both is refused.

inheritable has no effect on parent data: whether or not it is inheritable, a ParentDataModifier cannot be a component default, folds, and fails under a parent its protocol refuses.