Non-Double Discount Books
All the books contained on the list CAN have SCHSTAFF (or any other discount code) applied
NB: This only works when all exclusions are listed and 'all conditions' is ticked below
In other words...
List excludes books/bundles that cannot have the SCHSTAFF etc. discount applied (because they are already marked down by 15%)...
Also, include all titles in the conditions list that are already discounted... such as when SF Said's books are marked down for everyone