/sys$common/syshlp/helplib.hlb CC, Messages, UNAVOLACC  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        volatile access appears unaligned, but must be
                aligned at run-time to ensure atomicity and byte
                granularity

 Description    The compiler has detected an unaligned access to a
                volatile variable.  Because the access is unaligned,
                there is no guarantee of atomicity and byte
                granularity.  Therefore the access may not work as
                you expect.

 User Action    Make sure volatile objects are aligned on a natural
                boundary.