The European borders are lined with long lists of what may and may not be imported into the Union. For example peanuts may be imported but peanut butter may not, and priority is given to Greek and Spanish tomatoes above tomatoes grown outside the European Union. The lists also include criteria limiting the free movement of persons within the European Union. The Turkish trader who has lived, say, in the Netherlands for many years may ship his walnuts to Paris, but he may not bring them to Paris himself.
All these rules and sub-rules have become an incredibly confusing knot. Open Borders Behind Closed Doors unties the knots in text and cartoon strips.