The cork stoppers covered by the scope of this document are cork stoppers as defined in ISO 633, Cork Vocabulary, including natural cork stoppers, agglomerated cork stoppers, micro-agglomerated cork stoppers, multi-piece cork stoppers, 1+1 cork stoppers, and any other stoppers defined as cork stoppers. This document is applicable to the calculation of the carbon footprint (CFP) of cork stoppers from cork oak forest management through to the end-of-life stage of the stopper. This document establishes the principles, requirements and guidelines for the Product Category Rules (PCR) for cork stoppers within the framework of a Type III environmental declaration or a carbon footprint communication programme based on life cycle assessment (LCA) in accordance with ISO 14067. It also provides guidance on how to address and integrate additional environmental information, whether or not it is based on an LCA, in a consistent and scientifically sound manner in accordance with ISO 14025.