INCOMPDEREF

Message        <Context> "<expression>" is a pointer to an
               incomplete struct or union and should not be used as
               the left operand of a member dereference.

Description    In certain modes, HP C will allow the struct or union
               specifier of a member dereference operator (->) to
               specify a struct or union that does not contain the
               element specified by the right operand.  While this
               is considered poor programming practice, it was
               common with older C compilers.  In cases where the
               left operand is a pointer to an incomplete type, the
               practice is considered even worse.  While HP C will
               accept the construct in certain modes, the code
               should be modified.  Further, this program does not
               conform to the C standard and might not be accepted
               by other C compilers.

User Action    Be aware of this if you wish to port the program.