Chapter 2 explains the procedural character of Article 36 and examines its origins. It first tests the possibility that Article 36 represents a restatement or revised version of a similar provision found elsewhere in the law of armed conflict. To that end, it explores 13 international instruments that regulate the use of weapons in war and that were adopted prior to the 1974-1977 Diplomatic Conference where Article 36 was negotiated. The analysis reveals that none of the pre-existing international compliance mechanisms resemble the AP I weapons review provision. The chapter then examines the drafting materials. Whilst no unequivocal evidence on the motives for adopting a provision on weapons review can be found in the Official Records of the 1974-1977 Diplomatic Conference, there is sufficient evidence to conclude that the key States behind Article 36 were Germany and the United Kingdom. The General Legal Provisions relating to the Conduct of Hostilities and War on Land, operative in Germany since 1961 and mandating that weapons be developed in accordance with the requirements of existing legal regulations, might well be a predecessor to Article 36. [182 words]