The International Organization for Standardization (ISO) has published standard ISO/TS 80004-13:2017, “Nanotechnologies — Vocabulary — Part 13:  Graphene and related two-dimensional (2D) materials.”  According to ISO, over the last decade, interest has arisen in graphene due to its “many exceptional properties.”  More recently, other materials with a similar structure have also shown promising properties, including monolayer and few-layer versions of hexagonal boron nitride, molybdenum disulphide, tungsten diselenide, silicene, germanene, and layered assemblies of mixtures of these materials.  The thickness of these materials is constrained within the nanoscale or smaller and consists of between one and several layers.  These materials are thus termed two-dimensional (2D) materials as they have one dimension at the nanoscale or smaller, with the other two dimensions generally at scales larger than the nanoscale.  ISO states that 2D materials are a significant subset of nanomaterials, and it is important to standardize the terminology for graphene, graphene-derived, and related 2D materials at the international level, as the number of publications, patents, and organizations rapidly increases.  According to ISO, these materials need an associated vocabulary as they become commercialized and sold throughout the world.  The standard lists terms and definitions for graphene and related 2D materials, and includes related terms naming production methods, properties, and their characterization.  ISO intends the standard to facilitate communication between organizations and individuals in research and industry, other interested parties, and those who interact with them.