Controlled Vocabulary: words that has definitions and represented by a code, RxNorm is an example of a Controlled Vocabulary.
“RxNorm is two things: a normalized naming system for generic and branded drugs; and a tool for supporting semantic interoperation between drug terminologies and pharmacy knowledge base systems. The National Library of Medicine (NLM) produces RxNorm.” Source
ICD-10 is another example of Controlled Vocabularies
