# Introduction

## Background

SNOMED CT is a clinical terminology with a comprehensive coverage of wide clinical specialties and requirements. The development and maintenance of SNOMED CT relies on Description Logics (DL) and its reasoning services. The stated relationship file has been used to represent DL definitions. However, it is unable to fully represent semantics of the DL expressivity due to the limitation of its relational structure.

The new OWL refsets are designed to replace the stated relationship file and it represents the DL definitions for SNOMED CT content by following the international standard of OWL 2 Web Ontology Language.

## Purpose

The purpose of this document is to define and describe the OWL Reference Set.

## Scope

The document presents the specification of OWL refsets. It also documents the background, design considerations, quality assurance, and distribution format of the OWL refsets.

The implementation of the OWL refsets in the applications, and transformation of it to an OWL ontology, are out of the scope.

## Audience

The target audiences of this document include:

* SNOMED CT national release centers;
* SNOMED CT terminology content developers and technical developers;
* SNOMED CT implementers, analysts, and developers of electronic health records and information systems.

<a href="https://docs.google.com/forms/d/e/1FAIpQLScTmbZIf0UEQwYDkY27EEWBkaiYkHSbR0_9DmFrMLXoQLyL7Q/viewform?usp=pp_url&#x26;entry.1767247133=OWL+Specification&#x26;entry.670899847=1.%20Introduction" 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/snomed-ct-specifications/snomed-ct-owl-reference-set-specification/introduction/1-introduction.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.