There is no description for system preference EmailOverduesNoEmail It should be part of the chapter Global system preferences > Administration > interface options See: https://koha-community.org/manual//23.05/de/html/administrationpreferences.html#interface-options Text for manual: Asks: ___ overdue notices for patrons without email address to staff. Default: Send Values: Don’t send Send Description: If this system preference is enabled overdue notices for patrons without email address to staff (see system preference AddressForFailedOverdueNotices).
Added to the manual :-)