Why are trade rules required for Members' regulations? Part of the reason lies in the emergence of non-tariff barriers as a form of disguised protectionism. Some examples of such non-tariff barriers could include domestic regulations on the sale of goods, labelling, pricing, storage and value-added taxation, etc. Members negotiate commitments to ensure the transactions which take place at the border are as fair and as open as possible. It would be pointless if the benefits of these commitments were nullified by transactions which re-introduce the protection or discrimination that WTO rules seek to eliminate.