On this page: https://koha-community.org/manual/17.11/html/03_tools.html, this statement is not true: "Important When working with the overdue notices you want each notice at each branch to have a unique code. Think about using the branch code in front of the notice code for each branch."
I have reported it on the koha-manual bug tracker: https://gitlab.com/koha-community/koha-manual/issues/11
https://gitlab.com/koha-community/koha-manual/merge_requests/139