Typo in knotc documentation
The man/doc for knotc zone-purge contains the following description:
Purge zone data, zone file, journal, timers, and/or KASP data of specified zones. Available filters are +expire, +zonefile, +journal, +timers, and +kaspdb. If no filter is specified, all filters are enabled. It the zone is no longer configured, add +orphan filter (zone file cannot be purged in this case).
There is a typo in "It the zone is no". It should probably read "If the zone is no"
Reference: