This International Standard provides guidance on the specification of technically specified rubber (TSR). A grading system is proposed, based on the origin of the natural rubber content and on properties exhibited by the rubber. This International Standard is intended for use by parties involved in the procurement of TSR, and is intended to form a basis from which requirements for a particular case may be more closely specified. As such, it describes a number of criteria that need to be the subject of appropriate agreement between the interested parties.