It became recently possible to cancel an issued reminder. It was always possible to delete an issued reminder. Now we have the case where an user deleted the issued reminder document but actually wanted to cancel the reminder. Now that the reminder is deleted, it is not possible anymore to cancel the underlying reminder entries.

Next to this, it is not advised to delete issues reminders. Although they aren't official sales documents, they can be linked to GL entries (f.e. fee). Therefore it is necessary to block the possibility to delete issued reminders. I think it would be best if the existing sales & receivables setup parameter "allow document deletion before" would also apply / activated when trying to delete an issued reminder document.