Shredder no_tickets


what does the parameter no_tickets looks for and how to use it ?
i set status to ‘any’ and ‘no_tickets’ = 1 to show me all users who do
not have any relation to a ticket (watcher(Requestor, Owner, Cc or
AdminCc)). So i guess ‘no_tickets’ = 0 means show me users that have a
relation to at least one ticket.
The strange effect in my case is that i have several users who get
listed in both terms, how can that be ?
i also tried with true and false but makes no different.

A second question i have is the relation between an user and an
attachment. Does the shredder script also looks for this relation, or is
there only a direct relation between an attachment and a ticket and than
between a ticket and a user (what about TransactionId) ?

If i understand well, the shredder script checks all dependencies an
user can have to a ticket (watcher(Requestor, Owner, Cc or AdminCc)).

Best regards