If you delete a topic when no instances of that topic are left in the hierarchy,
a dialog 'KSW Topics Leave No Instance' is displayed. If a selection of items is deleted,
the user can check those items that will be excluded (or moved to 'Available Topics',
depending on the setting in Options > Application Options > When deleting topics that
leave no instance). Because no instance is left, such topics must be removed from the
index too, including all terms that are based on them.
So we wanted to delete a topic, but no instance of that topic is left in the hierarchy.
Then all traces of that topic will be removed from the index too, including terms that are
based on it. But where does this topic go after it is deleted? There are two
possibilities:
• Topic is added to 'Available Topics' (default), or
• Topic is excluded.
Whether one or the other of the above takes place, it depends on the setting in Options >
Application Options > When deleting topics that leave no instance. If you didn't change
this option, such a topic is always added to 'Available Topics'. If you opted for
excluding such topics, they'll be listed as 'valid' in 'Excluded Files', from where you
can restore them anytime (see Exclusions).