Chapter 9 explains the provisions contained in the Agreement on Safeguards in order to provide special and differential treatment for the benefit of developing countries. It notes that Articles 9.1 and 9.2 are provisions that refer to different aspects of this treatment. Article 9.1 allows the exclusion of imports from developing countries if they are introduced below certain individual and collective thresholds. It is an obligation that arises at the time of application of a safeguard measure and there is no requirement to explain the exclusion of these countries. Article 9.2, on the other hand, is a provision that allows developing countries to impose safeguard measures beyond the maximum period provided in Article 7 of the agreement. While the prerogative is contemplated in the national legislation of some developing countries, there has never been a safeguard measure that has been notified to the WTO with a duration permitted in Article 9.2.