Change a note to be 'inactive' to hide it from the default list view, and the details tab of the contact record. Change a note to be inactive once the tasks are complete. Inactive notes can still be located in notes list by using the filters.
Go to: notes list and Select the check box(es) on the row left for each item you want to mark as inactive. Click the multiple rows action button and choose 'set as not active'.
The list refreshes and the item(s) have been hidden from the default list view.
Use the list filter 'all' to find both active and inactive contact notes.
A strike-out style is applied to notes that are inactive.