FDA

The UNII is one of the core components of the United States Federal Medication Terminology
FDA Unique Ingredient Identifier (UNII)

FHIM

Federal Health Information Model

HL7

HL7 provides a framework (and related standards) for the exchange, integration, sharing, and retrieval of electronic health information. The standards define how information is packaged and communicated from one party to another, setting the language, structure and data types required for seamless integration between systems. HL7 standards support clinical practice and the management, delivery, and evaluation of health services, and are recognized as the most commonly used in the world.

HL7 Community
List of Freely Available HL7 standards

SNOMED International

SNOMED.org

ISO

ISO Standards
ISO Store