The words "preferential" and "non-preferential" in the Agreement does cause certain confusion. In the WTO context, preferential trade regimes cover free trade agreements and other autonomous preferential regimes, such as Generalized System of Preferences. Therefore, although MFN tariffs can actually be more favorable as compared to those applied to goods originating in non-WTO countries, they are considered "non-preferential" because they are applied to all members in the same manner without discrimination. Moreover, as trade within the WTO now accounts for roughly all world trade, transactions with countries outside the WTO are negligible in value. This is the reason why these days very few WTO members still require the submission of a non-preferential certificate of origin to apply MFN tariffs, but will apply them automatically.