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

 Message        <Context> the type of this argument to <function
                name> is not appropriate for the precision argument
                of the conversion specifier "<incorrect conversion>".
                Behavior can be unpredictable.

 Description    This argument corresponds to an output precision
                specification.  C requires that this argument have
                integer type, and it does not.

 User Action    Cast the argument to an int type.