The items in the Trashed Items section are not deleted unless the option to permanently delete them is selected. To enable permanent deletion follow these steps:
1. Log into Signals Notebook as and administrator
2. Navigate to System Configuration > System Settings > Other > Deletion
3. Select the 'Permanent Deletion' check-mark
4. Click 'Save Settings'
When the feature is enabled the Trashed items will be deleted after 30 days. This is a permanent delete with no possibility of recovering the data. This change affects all users in the tenant.