A description may be created in an extension as part of the process of adding a new concept, or adding a translation or alternative synonyms to an existing concept. Extension descriptions are distributed in a description file, which follows the standard RF2 release file format. For more details on the principles and processes for authoring descriptions in an extension, please refer to 5.4.3 Authoring Descriptions.
Attributes
In addition to the four common attributes, descriptions also have a conceptId, languageCode, typeId, term and caseSignificanceId.
conceptId
The conceptId attribute links the description to the concept that it describes. The conceptId may refer to a concept in the same extension module or to a concept in a module on which the extension module depends.
languageCode
The languageCode is a two-character string, which specifies the language of the description using the ISO 639-1 standard (e.g. 'EN', 'ES'). Please note that the languageCode specifies only the language of the description (e.g. English or Spanish) and does not indicate the dialect (e.g. US English or GB English). Dialect preferences are represented by language reference sets. Extensions may use a languageCode not used by the International Edition.
typeId
The typeId is a SCTID that specifies the type of the description. The value of this attribute must be a descendant of 
. Possible values include 
, 
, and 
. Note that is used for text definitions, which are not included in the main description distribution files. Instead, descriptions of type are distributed in a separate text definitions file.
term
The term attribute is a text string that describes the given concept. The term is represented using UTF-8, which allows non-English character sets to be used, such as the accented characters used in Nordic languages, Hindi characters and Chinese characters. The maximum length of a fully specified name or synonym is defined in the 
as 255 characters. Longer terms can be used for text definitions, which may be up to 4096 characters in length.
caseSignificanceId
The caseSignificanceId attribute is a SCTID which specifies how the case of the characters in the term may be changed when using the term. The values of this attribute always refer to descendants of the concept 
, and at the time of this publication, the three possible values are 
, 
,or 
.
Examples
In 
a row is presented from the descriptions table of the 20170901 US edition. Note that this description is associated with the extension concept from the previous example.
A row from the description table in the 20170901 US Edition |
Please note the following:
- The description id uses a namespace identifier allocated to the National Library of Medicine (NLM). This indicates that this description was created by the NLM.
- The description id uses a partition identifier of “11”. This indicates that the description was created in an extension.
- The moduleId indicates that this description is included in the
, which is the same module that the associated concept (from the previous example) is included in. - The description id and the conceptId both use a namespace identifier owned by the NLM. This indicates that this description is associated with a concept created by the same extension producer.
- A languageCode of "en" indicates that this description uses the English language.
- The typeId indicates that this description is a .
- The term indicates that the string "Persistent asthma" is used to describe the concept
. - The caseSignificanceId indicates the term is . This means that the term can be displayed using any alternative casing, such as "PERSISTENT ASTHMA" and "persistent asthma".
In 
a row is presented from the descriptions table of the 20170430 Canadian edition. Note that this description is associated with a concept from the International Edition.
A row from the description table of the 20170401 French Canadian extension |
Please note the following:
- The description id uses a namespace identifier allocated to Canada Health Infoway (CHI). This indicates that this description was created by the CHI.
- The description id uses a partition identifier of “11”. This indicates that the description was created in an extension.
- The moduleId indicates that this description is included in the
. - The conceptId refers to the concept
from the International Edition. This indicates that this term may have been created as a language specific term for an international concept. - A languageCode of "fr" indicates that this description uses the French language.
- The typeId indicates that this description is a .
- The term indicates that the string "herpès labial (trouble)" is used to describe the concept . Please note the semantic tag, "trouble" is a French word for "disorder".
- The caseSignificanceId indicates the term is . This means that the term can be displayed as either "Herpès labial (trouble)" or "herpès labial (trouble)".