> For the complete documentation index, see [llms.txt](https://docs.snomed.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snomed.org/education/snomed-ct-education-editorial-guide/readme/concept-model-overview/qualifying-characteristics.md).

# Qualifying Characteristics

<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>

A *qualifying characteristic* is expressed by an attribute-value pair. The attribute may have one value, from a range of values, based on the domain's concept model. If a particular qualifying characteristic is applied to a concept, the resulting expression represents a more tightly defined subtype of that concept.

{% hint style="info" %}
Clinical expressions using SNOMED CT concepts can be of two types: precoordinated expressions, which use a single SNOMED CT concept identifier; and postcoordinated expressions, which contain more than one SNOMED CT concept identifier.
{% endhint %}

For example,

* It might be possible to qualify a disorder such as

  53084003 | Bacterial pneumonia (disorder)| according to its clinical course (373933003 | Acute onset (qualifier value)| or 90734009 | Chronic (qualifier value)|) or severity (255604002 | Mild (qualifier value)|, 6736007 | Moderate (severity modifier) (qualifier value)|, or 24484000 | Severe (severity modifier) (qualifier value)|)
* 125605004 | Fracture of bone (disorder)| can be refined by qualifying it with 12611008 | Bone structure of tibia (body structure)| to represent the concept 31978002 | Fracture of tibia (disorder)|

<a href="https://docs.google.com/forms/d/e/1FAIpQLScTmbZIf0UEQwYDkY27EEWBkaiYkHSbR0_9DmFrMLXoQLyL7Q/viewform?usp=pp_url&#x26;entry.1767247133=SCT+Editorial+Guide&#x26;entry.670899847=Qualifying%20Characteristics" class="button primary">Provide Feedback</a>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://docs.snomed.org/education/snomed-ct-education-editorial-guide/readme/concept-model-overview/qualifying-characteristics.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.