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4.5.3 Restrictions on Vocabulary Domains
Following is an example of a Vocabulary Specification Schematic which is an output of - 3.3.1 


Restrictions on Vocabulary Domains


Build design models of static information views:

A vocabulary domain consists of a set of concepts, not a set of words or codes. In different contexts, the same concept could be represented using different coding systems. Thus, each concept in a vocabulary domain has a one-to-many relationship to codes that might be used as representations for the concept in a message instance. 

 4.6.3.1 Extensibility Qualifiers 
The context in which a vocabulary domain is used specifies the extensibility rules for a domain. 

If a domain allows values other than those specified by its value sets, the extensibility qualifier will be “Coded with extensions”. Otherwise the value sets must be used as specified and the extensibility qualifier must be “Coded, no extensions”. CS (coded specifier) data types are by default CNE. 

If a domain is specified as “Coded, no extensions” (CNE), any of its restrictions must maintain the same extensibility qualifier. 

 4.6.3.2 Vocabulary Domain Taxonomy
Vocabulary Domains apply to coded attributes of RIM classes as follows:

Structural Vocabulary Domains apply to those coded HL7 invariants such class type, mood, status, etc. Structural codes are part of the HL7 syntax and thus may not be constrained routinely during the process of developing specification. These codes may be constrained or extended only if the changes are also subject to harmonization. The Extensibility Qualifier (coding strength) for these domains is specified as “Coded, no extensions” (CNE) 
Clinical Vocabulary Domains apply to those coded attributes that describe healthcare coded concepts and not syntax. Depending on the context, Extensibility may be set to “Coded with extensions” (CWE) or CNE. 
External Vocabulary Domains apply to those coded attributes that are based on an externally defined Code System which is simply referenced by HL7. 
[[TBD]] Local Realm to vocabulary domain