This International Standard - provides set of data type definitions for representing and exchanging basic concepts that are commonly encountered in healthcare environments in support of information exchange in the healthcare environment, - specifies a collection of healthcare related data types suitable for use in a number of health related information environments, - declares the semantics of these data types using the terminology, notations and data types defined in ISO 11404 rev 2005, - provides UML definitions of the same data types using the terminology, notation and types defined in Unified Modeling Language (UML) version 2.0, - defines an XML (Extensible Markup Language) based representation of the data types suitable for use when exchanging information between information processing entities. The requirements which underpin the scope reflected are a mix of requirements gathered primarily from HL7 Version 3 and ISO 11404, and also from CEN 13606 and past ISO work on healthcare datatypes. Although the focus with regard to requirements and design approaches has focused on the information interchange, these datatypes may be adopted for other purposes in healthcare, but this is not mandated by this standard.