**Description:**The actual value is not a member of the set of permitted data values in the constrained value domain of a variable. (e.g., concept not provided by required code system).

Usage Notes: This flavor and its specializations are most commonly used with the CD datatype and its flavors. However, it may apply to *any* datatype where the constraints of the type are tighter than can be conveyed. For example, a PQ that is for a true measured amount whose units are not supported in UCUM, a need to convey a REAL when the type has been constrained to INT, etc.

With coded datatypes, this null flavor may only be used if the vocabulary binding has a coding strength of CNE. By definition, all local codes and original text are part of the value set if the coding strength is CWE.