Revise existing Foundation Vocabulary Introduction
The current Vocabulary Introduction section is sufficiently ambiguous that it needs to be updated prior to the next ballot.
The Discussion page is to be used for suggested changes:
Modern health care communications and data storage makes heavy use of encoded information. In HL7, this is referred to as vocabulary. The HL7 standard defines several different type of objects that implement various characteristics of vocabulary. Whereas other section of the HL7 standard are primarily concerned with structure, vocabulary deals with content.
Consistent with the version 3 philosophy of successively constraining an abstract information model, the least constrained category in vocabulary is a Concept Domain. See: Revised existing Glossary An HL7 Concept Domain is a named category of like concepts (semantic type) that will be bound to one or more coded elements.* Concept Domains exist because we want to constrain the intent of the coded element while deferring the association of the element to a specific coded terminology until later in the message development process. Thus, Concept Domains are independent of any specific vocabulary or code system.
The categorization of Concept Domains is hierarchical allowing for further constraint on the breadth of the semantic category covered by the Concept Domain. Such constrained domains are known as “sub-domains”. Sub-domains allow for further specialization (constraint) on the intended values for a domain.
A list intended values for a concept domain or sub-domain is referred to as a value set. A value set consists of one or more concept codes. These are the possible concept codes that can be carried in an HL7 Version 3 message. When a value set is associated with given concept domain or sub-domain, this is called "binding". Different value sets can be associated with the same concept domain in different circumstance...
A concept code is only unique within a particular context. As an example, "M" may stand for male in one context and married in a second. The context in which a concept is defined is called a 'code system. Many code systems already exist in the medical domain, such as ICD-9, SNOMED-CT, etc. Whenever possible, HL7 reuses existing concept codes rather than developing their own. ...
At the point that message designers and implementers decide on the specific terminology to represent the information payload of a coded element, a value set is bound to the coded element.
The vocabulary domain name and the associated extensibility qualifier for each coded attribute in the RIM are specified in the RIM narrative. This specification occurs as the first line of the attribute's description in the following format:
Vocabulary Domain: "MyVocabularyDomain" (CWE)
There is a link between the vocabulary domain name in the RIM listing and its entry in the HL7 Vocabulary Domain Values table in this listing.