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

 Message        <Context> for the function "<name>", the implicit
                return type of "<type>" is not consistent with the
                expected type of "<type>".  It will be treated as an
                ordinary implicitly defined external function.

 Description    A function that could be handled internally by the
                compiler has not been declared, so an implicit
                declaration has been created for the function.  The
                return value for the function is being used, and the
                implicit return type does not agree with what the
                compiler expected to see.  In such cases, the
                function will not be handled internally, but will
                instead be called at run time in the usual manner.
                This could result in a performance loss, or possibly
                incorrect results if the implicit return type is
                incorrect.

 User Action    If the function is intended to refer to the runtime
                library routine, the appropriate header file should
                be included in the source.  Alternatively, a correct
                prototype could be provided privately in the source
                file.  If the function is intended to be a
                replacement for the runtime library routine, disable
                the intrinsic version by specifying "#pragma
                function(function_name)" in the source file.