7.6.3 Message selection

`-< number'

`--less-than=number'

Print messages with less than number definitions, defaults to infinite if not set.

`-> number'

`--more-than=number'

Print messages with more than number definitions, defaults to 1 if not set.

`-u'

`--unique'

Shorthand for `--less-than=2'. Requests that only unique messages be printed.