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

 Message        <Context> type long double has the same
                representation as type double on this platform.

 Description    Although Compaq C will recognize the long double type
                as a different type than double in this compilation
                mode, on this platform they will both use the same
                representation.  Using long double will not provide
                any additional precision or range.

 User Action    Be aware of this.