ISO 27917:2017 defines a list of cross-cutting terms commonly used in the field of carbon dioxide capture, transportation and geological sub-surface storage including through storage in association with enhanced oil recovery (EOR) operations. ISO 27917:2017 only deals with CO2 geological sub-surface storage. The terms are classified as follows: - general terms and definitions relating to carbon dioxide; - general terms and definitions relating to carbon dioxide capture, transportation and storage; - general terms and definitions relating to monitoring and measuring performance in carbon dioxide capture, transportation and geological storage; - general terms and definitions relating to risk; - general terms and definitions relating to relationships with stakeholders; A list of the main acronyms used is given in Annex A.