`--dbmask` *none*|*dust*|*soft*
: Mask regions in the database sequences using the *dust* method or
  the *soft* method, or *none* to suppress masking. See
  [`vsearch-mask(1)`](./vsearch-mask.1.md) for more details. Warning,
  when using *soft* masking, search commands become case
  sensitive. The default is to mask using *dust*.
