We have several instances on one server. Some are using patron self registration, others do not. Now when cleanup_database.pl is run, we get a warning in the logs: Self-registrations cannot be removed, system preference PatronSelfRegistrationDefaultCategory is not set This is unnecessary, as for the libraries in question PatronSelfRegistration is OFF and PatronSelfRegistrationExpireTemporaryAccountsDelay is set to 0. The pref description says: NOTE: This system preference requires the misc/cronjobs/cleanup_database.pl cronjob. Ask your system administrator to schedule it. No patrons will be deleted if you set the pref to zero or make it empty. So we are telling the script, it's OK, we don't want any deleted, and still get the noisy warning. This is unnecessary. The warning should only be given when PatronSelfRegistrationExpireTemporaryAccountsDelay is not empty or 0 and the PatronSelfRegistrationDefaultCategory is empty at the same time. We might also want to check for PatronSelfRegistration.