# Plurals

<mark style="color:$danger;">**This Editorial Guide is used for Education Purposes Only. It is used in the Authoring Courses and Certifications. It is based on the January 2026 Editorial Guide.**</mark>

## Fully specified names (FSNs) <a href="#fully-specified-names-fsns" id="fully-specified-names-fsns"></a>

In general, concepts are represented in the singular, rather than the plural.

* For example:
  * |Disorder of lung (disorder)|, not |Disorder of lungs|
  * |Acute cholecystitis due to biliary calculus (disorder)|, not |Acute cholecystitis due to biliary calculi (disorder)

FSNs should not be plural unless the concept necessarily involves multiples.

## Unintended plurals <a href="#unintended-plurals" id="unintended-plurals"></a>

*Unintended plurals* might be incorrectly interpreted. An unintended plural is the use of a plural when, in fact, there is only one entity.

* Correct example:
  * *Multiple cranial nerve palsies*; the word *multiple* indicates that there can never be just one, so the plural *palsies* is correct
* Incorrect example:
  * *Trochlear lesion* versus *trochlear lesions;* users would use this concept to refer to a single trochlear lesion, thus the plural form would be incorrect

## Exceptions <a href="#exceptions" id="exceptions"></a>

Organizational nodes or grouper concepts may be plural.

* For example,
  * 234320004 | Procedures for splenic lesions (procedure)|
  * 194732001 | Diseases of mitral and aortic valves (disorder)|, has IS A 195002007 | Multiple valve disease (disorder)|

A concept that necessarily involves multiples should have a plural FSN.

* For example,
  * Bilateral atrophy of testes (disorder)

{% hint style="warning" %}
It is advisable to keep track of these exceptions in a separate subset or using a special term type, so that they can be excluded when the singular/plural distinction is important for mapping.
{% endhint %}

<a href="https://docs.google.com/forms/d/e/1FAIpQLScTmbZIf0UEQwYDkY27EEWBkaiYkHSbR0_9DmFrMLXoQLyL7Q/viewform?usp=pp_url&#x26;entry.1767247133=SCT+Editorial+Guide&#x26;entry.670899847=Plurals" class="button primary">Provide Feedback</a>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.snomed.org/education/snomed-ct-education-editorial-guide/readme/authoring/general-naming-conventions/plurals.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.