A.4 Mapping in more detail

A.4.2 Semantics of type mapping

The statement that an IDL type I is mapped to a Lisp type L indicates that if V is a Lisp value whose corresponding IDL type is I, then the consequences are not specified if the value of V is not a member of the type L. For example, if V is passed as a parameter to an IDL operation or if V is returned from an IDL operation, then a conforming implementation may reasonably perform any of the following actions if V is not of the type L.

If V may be coerced to L, then V may be replaced by the result of coercing V to the type L.
If V cannot be coerced to L, then an error may be signalled. If the error occurs during marshalling or unmarshalling,corba:marshal should be signaled.