The representation of the functional and clinically significant part of the active ingredient substance(s) present in a medicinal product, and as such the TM class is an abstract representation of a medicinal product without reference to strength and dose form, focusing only on active ingredient substance(s). This is a broad data exchange subset that is intended to support semantic interoperability and conformance testing. It is recommended that jurisdictions define and implement more specific clinically curated subsets that contain a portion of these concepts for data capture at the point of care for their specific use case. This subset is part of the Canadian Clinical Drug Data Set maintained by Health Canada. This resource is an informative value set; a normative subset containing the expanded values can be found on Canada Health Infoway's Terminology Server.