KEYWORD may have an occurrence specified in brackets
 following the name. This
enables testing for the existence of multiple occurrences. Note that it is not normal
to have multiple occurrences of a keyword in a FITS header, unless it is blank, COMMENT
or HISTORY. Any text between the brackets other than a positive integer is interpreted
as the first occurrence.
The suggested value is the current value.
FALSEdepending on whether or not the FITS keyword BSCALE exists in the FITS extension of the NDF called abc.
FALSEdepending on whether or not the FITS there are at least two occurrences of the keyword DATE.