OMOP/Documentation/CommonDataModel_Wiki_Files/StandardizedVocabularies/CONCEPT_SYNONYM.md

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

No.|Convention Description
:--------|:------------------------------------
| 1  | The concept_synonym_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. |
| 2  | 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. |
| 3  | Currently, only English Synonyms are included. |