The basic   data structure consists of the following fields:

Basic Reference Set Data Structure





Each   is identified and named by a   in the metadata hierarchy. Therefore the reference set is identified by a concept identifier (an  ). 

Each row in a reference set file represents a  .

The   and   fields will not change between two rows with the same id, in other words they are immutable. Where a change is required to one of these fields, the current row will be inactivated (by appending a row with the same id and the   field set to false). Another row with a new id will be appended to reference another component.

A component may belong to any number of  .  A component may also be referenced by more that one member of the same  . This is not useful in the case of a simple reference set but is relevant for some reference sets. For example, a SNOMED CT concept may map to or from more than on codes in another code system.