-output_no_hits option
Specifies that a record should be written to search or
clustering output files if there are no hits for
the query sequence. By default, no records are written except for
uc files, which always have N (no-hit) records for
unmatched queries.A star (*) is written in place
of the target label. Placeholders (zeroes or empty values) are written in other
fields of the record.