0                  Indicates that the conversion descriptor was
                       successfully deallocated.
    -1                 Indicates an error occurred. The function sets
                       errno to one of the following:

                       o  EBADF - The cd argument is not a valid
                          conversion descriptor.

                       o  EVMSERR - Nontranslatable OpenVMS error
                          occur. vaxc$errno contains the VMS error
                          code.