@property
    def field_specifier(self):

        # Ensure that the keyword exists and has been parsed--the will set the
        # internal _field_specifier attribute if this is a RVKC.
        if self.keyword:
            return self._field_specifier
        else:
            return None
The field-specifier of record-valued keyword cards; always `None` on
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/card.py/Card.field_specifier