VMS Help CC, Messages, NORELATIONAL  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> "<expression1>" and "<expression2>" cannot
                be compared with a relational operator.

 Description    Because of their types, the two expressions cannot be
                used as the operands of a relational operator.  The
                rules for which types can be used in a relational are
                rather complicated and differ based upon the compiler
                mode.  Refer to the language documentation for a
                complete list of valid combinations.

 User Action    Modify the relational to use valid types.  This can
                often be done by casting one of the expressions to
                the type of the other.