ISO 30042:2019 explains fundamental concepts and describes the metamodel, data categories, and XML styles: DCA (Data Category as Attribute) and DCT (Data Category as Tag). It also specifies the methodology for defining TBX dialects.The audience for this document is anyone wishing to create a new dialect compliant with TBX. This document can also be used to analyze and to understand a terminological data collection or to design a new terminology database that complies with international standards and best practices. Typical users are programmers, software developers, terminologists, analysts, and other language professionals. Intended application areas include translation and authoring.The TBX-Core dialect is described in detail in this document. All other industry-supported dialects are out of the scope of this document.NOTE TBX dialects are defined by industry stakeholders. Any materials needed to implement currently shared dialects are publicly available as self-contained industry specifications (see for instance the TBX Info website[15]).