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A 900000000000506000 |Language type reference set| supports the representation of language and dialects preferences for the use of particular descriptions. The most common use case for this type of reference set is to specify the acceptable and preferred terms for use within a particular country or region. However, the same type of reference set can also be used to represent preferences for use of descriptions in a more specific context such as a clinical specialty, organization or department.

Data structure

A Language reference set is a Component reference set that is used to indicate which descriptions contain terms that are acceptable or preferred in a particular language or dialect . Its structure is shown in the following table.

Table 4.2.4-1: Language reference set - Data structure


Data type


Part of Primary Key


A 128 bit unsigned Integer, uniquely identifying this reference set member.

Different versions of a reference set member share the same id but have different effectiveTime. This allows a reference set member to be modified or made inactive (i.e. removed from the active set) at a specified time.

NOYES (Full /Snapshot)

The inclusive date or time at which this version of the identified reference set member became the current version.

The current version of this reference set member at time T is the version with the most recent effectiveTime prior to or equal to time T .


YES (Full)

Optional (Snapshot) 

The state of the identified reference set member as at the specified effectiveTime .

If active = 1 (true) the reference set member is part of the current version of the set, if active = 0 (false) the reference set member is not part of the current version of the set.


Identifies the SNOMED CT module that contains this reference set member as at the specified effectiveTime .

The value must be a subtype of 900000000000443000 |Module (core metadata concept)|within the metadata hierarchy.


Identifies the reference set to which this reference set member belongs.

In this case, a subtype descendant of: 900000000000506000 |Language type|


A reference to the SNOMED CT component to be included in the reference set.

Refers to the description to which the acceptability value is being applied.




A subtype of 900000000000511003 |Acceptability| indicating whether the description is acceptable or preferred for use in the specified language or dialect .


Language Reference Rules and Guidance

In a Language reference set:


The following metadata supports this reference set :

Table 4.2.4-2: Language References Sets in the Metadata Hierarchy

900000000000454005 |Foundation metadata concept|
900000000000506000 |Language type|
900000000000507009 |English|
900000000000508004 |GB English|
900000000000509007 |US English|

The immediate children of |Language type| will represent languages. This level may be used to represent the "formal approved" language, where a language authority is formally recognized. In most cases, this level will not identify a specific reference set. Subtype of the language level are used to represent different dialects, national or regional variants.

Reference Set Descriptor and Example Data

Notes on the tables used to show descriptors and examples

The reference set example tables on this page have been revised as follows to aid clarity and understanding:

  • The first four columns which are present in all release files are not shown. The omitted columns ( id effectiveTime active moduleId) are used in the same way in all referenced sets to support identification, versioning and packaging. They do not directly affect the specific features of a particular reference set or reference set type.
  • Reference set columns that contain SNOMED CT identifiers are expanded to show details of the concept or description referenced by that identifier. In some cases, the term is shown in the same column using the expression syntax, in other cases an additional column with a name suffix '_term' has been added. In the standard reference set files only the identifier is present in the column and there is no added column for the term. When using reference sets, the term and other details of the component are looked up from the relevant component release files.

Language Reference Descriptor

The table below shows an example of the descriptor for a specific reference sets that follows the 900000000000506000 |Language type reference set| pattern.

Table 4.2.4-3: Refset Descriptor rows for a language reference set

Language Reference Set Examples

Table 4.2.4-4: Sample content from the US English language reference set

Table 4.2.4-5: Sample content from the GB English language reference set

In the above examples, 80146002 |Excision of appendix| is acceptable in both US and GB English. However, 80146002 |Appendectomy| is preferred in US English and 80146002 |Appendicectomy| is preferred in GB English.