VMS Help TCPIP Services, Programming Interfaces, Sockets API, gethostbyaddr(), Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    This function finds the first host record in the hosts database
    with the given address.
    The gethostbyaddr() function uses a common static area for its
    return values. This means that subsequent calls to this function
    overwrite previously returned host entries. You must make a copy
    of the host entry if you want to save it.