def _configSpecial_Volume3DOpts_clipPlane(target, parser, shortArg, longArg,
    helpText):
    """Configures the ``clipPlane`` option for the ``VolumeOpts`` class.
    This option allows a clip plane to be defined - the user provides
    the position, azimuth and inclination as a single argument.
    """
    parser.add_argument(shortArg, longArg, type=float, nargs=3, action=
        'append', metavar=('POS', 'AZI', 'INC'), help=helpText)
