===== CONCEPT_SYNONYM table =====
**THIS IS OUTDATED. All documentation is now on the [[https://github.com/OHDSI/CommonDataModel/wiki|github wiki]]. Please refer there or to the [[projects:workgroups:cdm-wg|CDM working group]] for more information**

The CONCEPT_SYNONYM table is used to store alternate names and descriptions for Concepts. 

^Field^Required^Type^Description^
|concept_id|Yes|Integer|A foreign key to the Concept in the CONCEPT table.|
|concept_synonym_name|Yes|varchar(1000)|The alternative name for the Concept.|
|language_concept_id|Yes|integer|A foreign key to a Concept representing the language.|

==== Conventions ====

  * The concept_name field contains a valid Synonym of a concept, including the description in the concept_name itself. I.e. each Concept has at least one Synonym in the CONCEPT_SYNONYM table. As an example, for a SNOMED-CT Concept, if the fully specified name is stored as the concept_name of the CONCEPT table, then the Preferred Term and Synonyms associated with the Concept are stored in the CONCEPT_SYNONYM table. 
  * Only Synonyms that are active and current are stored in the CONCEPT_SYNONYM table. Tracking synonym/description history and mapping of obsolete synonyms to current Concepts/Synonyms is out of scope for the Standard Vocabularies.
  * Currently, only English Synonyms are included.