Deleting at Maintenance Task List Level 
Use
You should delete at maintenance task list overview level when you want to delete several maintenance task lists, in other words, group counters, at the same time.
The system then sets a deletion indicator that you can no longer undo. The group counter is logically deleted and will no longer be displayed at the maintenance task list level.
Procedure
You will come to a dialog box with a confirmation prompt.
If you do want to delete the group counter, confirm this by pressing Yes.
Once you have confirmed, the system produces a message to inform you that the group counter will be flagged with a deletion indicator.
The group counters you selected disappear from the TL overview.
The system enters the deletion indicator in the task list header of each group for each group counter selected.
Result
The system archives and deletes the maintenance task list the next time the archiving program is run.