Existing Wording: Data elements (and their registries) and codes (and their code systems) serve different purposes. Data elements describe the characteristics of a piece of data while codes describe a particular concept (often in relation to other concepts). However, because data elements provide a definition of the meaning of a particular element, they can be thought of as being codes. One of their purpose is to define variables, observations, or questions, that include information about how to collect a variable's value--including information about data types, and guidance about the use of about answer lists and/or units of measure. This function is typically done by code systems such as LOINC and SNOMED CT. (Note that LOINC provides considerable detail about allowed answers, while most other code systems such as SNOMED only allow identifying the question.)It would be possible to treat a registry of data elements using a common identifier system/namespace as a code system. Similarly, data elements can be mapped to each other (and to codes) in the same manner as codes can be mapped by making use of the ConceptMap resource.

Comment:

see tracker item 6266