At the top of the Patron module (every tab) - What object/item does the "Search my RSQueue" icon represent? Is it a clip board? Been wondering for years....
I think you've got it--looks like a clipboard with little red checks (perhaps to indicate that you are "checking" on your patrons)!
That icon opens your RSQueue in the patron window as a query, but if you want a checklist to browse through, you can also open a handy new window using the RS Queue Navigator. That opens from your Functions menu > Profile > RS Queue Navigator.