Fully specified name (FSN) definition |
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A term unique among active descriptions in SNOMED CT that provides the meaning of a concept in a manner that is intended to be unambiguous and stable across multiple contexts. |
For information on acceptable precoordinated naming patterns, see the Pre-coordination Naming Patterns project. New content should conform with the naming patterns; however, legacy content may not yet be updated. |
An FSN is one type of description, unique among active descriptions in SNOMED CT. It provides the meaning of a concept so that it is unambiguous, stable across multiple contexts, and optimally understandable to those whose first language is not English. Consequently, it is not always clinician-friendly or in common use. In the majority of cases, where the FSN is clinician-friendly and in common use, a description matching the FSN should be added to the concept. This description is not required to be the preferred term (PT). In certain instances, where the FSN does not provide a clinically useful description, a matching description without the semantic tag is unnecessary.
For example,
Choledochoplasty is marked as preferred in the US English Language Reference Set; choledochoplasty is the preferred term for this concept in US English.
Each new content request should have an FSN that conforms to spelling, language, and style guidelines. It should also have SNOMED CT parent concepts that conform to editorial guidelines and show where in the hierarchy it belongs. In the Content Request System (CRS), if the meaning of the FSN is unclear or the parent codes are not provided, authors should request the information from the submitter.
A well formed FSN includes:
An FSN with an approved disjunctive (although not often used), e.g. Traumatic and/or non-traumatic injury of back (disorder), should have lower case and/or.
An FSN should not have:
Exceptions that should not be amended include:
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When constructing the FSN for a disorder, finding, or procedure containing a body structure, the wording of the body structure should follow the naming convention of the body structure concept. However, it should not include the words structure or structure of. For example,
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The FSN is unique among active concepts. The SNOMED International Authoring Platform automatically creates a matching description to the FSN. Authors then determine the clinical usefulness of a synonym that matches the FSN. Those that are useful are maintained in SNOMED CT; those that are not useful are removed. The Authoring Platform displays a warning when the matching description is removed; however, this does not prevent the author from saving the concept.
The FSN should provide a linguistic representation of the concept in an unambiguous way. It is considered an anchor for the representation of meaning of a concept, to which modelers can refer, when assigning a logic-based definition. The FSN does not necessarily follow the usual phrasing used in clinical practice; it may be phrased differently and may be longer and more fully spelled out in order to represent the meaning as clearly as possible and globally communicate the intended meaning of the concept.
The characters comprising the description, as well as case significance, must be taken into account to provide for a unique FSN. Uniqueness maintained through case sensitivity is handled by the "case significance indicator". It is possible to alter the semantics of concepts whose FSN uniqueness depends upon case significance.
For example,
38194003 |Weak e phenotype (finding)|
6800004 |Weak E phenotype (finding)|
The two referenced concepts above could easily be mistaken for duplicates if not for varying case sensitivity indicators that demarcate each concept's uniqueness.
A single term may have more than one meaning. Therefore, FSNs should be checked for ambiguity.
For example, immunosuppression may mean the state of being immunosuppressed, or it may mean the application procedure of immunosuppressive therapy.
The following FSNs are clear and acceptable.
For example,
The following FSNs are ambiguous, and the concept should be inactivated.
For example,
Minor changes to an FSN are allowed without inactivation of the concept. When making a minor change to an FSN, a new description must be created and the old description must be inactivated. While the description ID will change, the concept ID remains the same. FSN changes cannot change the meaning of the FSN. Minor changes include:
Where an active concept requires an update to the FSN to conform to current editorial guidance, this may result in duplication with the FSN on an inactive concept.
In this scenario:
For example,
Concept 27215002 had an FSN of Uterine inversion (disorder). Editorial policy instructs this to be formatted as Inversion of uterus (disorder). However, an inactive concept of 156232008 |Inversion of uterus (disorder)| already exists with that FSN. 156232008 |Inversion of uterus| is named correctly but has been inactive since 2002. In this case, the concept 27215002 should remain active with its FSN updated.
The inactive concept, 156232008 |Inversion of uterus|, should be checked to ensure its inactivation reason is ‘Duplicate’ and the Association type ‘SAME_AS’ to the active concept 27215002 with the same FSN.
For circumstances where a new concept duplicates an inactive concept with the same FSN, the inactive concept should be reactivated rather than adding a new concept. |
Some FSN changes are necessary for style consistency; again, changes are only acceptable if the meaning does not change.
They may include changing:
For example,
When changing a concept's semantic tag within the same top-level hierarchy, use the description inactivation reason of Non-conformance to editorial policy.
Major changes to FSNs require inactivation of the concept. The following are examples of major changes, when:
The FSN for a concept in the International Release is designated an International FSN. The International FSN is considered the gold standard for interpretation of the meaning of the concept, from a linguistic standpoint.
The logical definitions, represented using the concept model, should represent the same meaning. Spelling of the International FSN follows United States (US) English spelling conventions. Other English language spelling and conventions, such as Great Britain (GB) English, may be represented in preferred terms and other descriptions. They should be appropriately tagged using the Language Reference Set mechanism.
For example,
Acronyms are easily misinterpreted. For this reason, all acronyms are unacceptable in FSNs.
For example, the FSN should be the expanded form, Computed tomography of chest (procedure), however as a preferred term, CT of chest (procedure) is acceptable.
If there is an acronym in an existing FSN, the FSN DescriptionId is inactivated and a new FSN is created (regardless of whether or not the acronym was in parentheses with the expanded form). The replacement FSN concept has the expanded description with the acronym entirely removed. Inactivating the ConceptId is not necessarily required, unless the FSN had significant ambiguity before changing it to its expanded form.
Before any changes are made to an FSN, imported directly with an extension (local) ID, the submitter should be notified and confirmation sought that no loss of meaning has occurred. This helps to ensure that the original meaning is understood and maintained. Authors should:
Changes to existing SNOMED CT concepts do not necessitate notifying the original submitter. |