This Technical Report specifies the procedure on how to evaluate and treat the most commonly found manufacturing imperfections on seamless steel and aluminium alloy gas cylinders at visual inspection at the stage of product acceptance.Annex A contains a template for the relevant cylinder design International Standards (i.e. ISO 9809-1, ISO 9809-2, and ISO 9809-3 for seamless steel and ISO 7866 for seamless aluminium alloy cylinders). It further contains information on how to implement the provisions into other cylinder design standards.