You can use the script below to see how many recurring lines are assigned each Item. This script also shows which Recurring Line Descriptions are different than the actual Item Description if the customer would like that cleaned up.
select b.item_code as "Invoice Item",
b.inactive as "Invoice Item Code Inactive Y/N",
--b.item_id,
count(c.item_id) as "Number of Recurring Lines with Invoice Item Code",
b.description as "Invoice Item Description",
c.user_description as "Recurring Line Description"
from ar_item b, ar_customer_recurring c
where c.item_id=b.item_id and c.Customer_Id > 1
group by b.item_code, b.inactive, b.item_id, b.description, c.User_Description
order by b.item_code