> 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/authoring/general-naming-conventions/us-vs-gb-english.md).

# US vs. GB English

<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>

All fully specified names (FSN) should be represented in US English. When there is a difference between the US and GB spelling, there should be US and General British (GB) preferred terms (PT) and/or synonyms (SYN).

* For example:
  * FSN: Benign tumor of endocrine pancreas (disorder)
  * PT-US: Benign tumor of endocrine pancreas
  * PT-GB: Benign tumour of endocrine pancreas

{% hint style="success" %}
**Proper nouns**

Where an FSN represents the name of an organization or trademarked name, a synonym with variant GB or US spelling is not required.
{% endhint %}

<table><thead><tr><th width="201.65625">References for Spelling</th><th>References</th><th>Notes</th></tr></thead><tbody><tr><td>US-GB differences</td><td><p>Wikipedia, the free encyclopedia*</p><p>*Note: Wikipedia may be used as a starting point, or source, for authoritative references, but not as an actual reference</p></td><td><ul><li>First point of reference</li><li>Provides a summary for authors, addresses many US-GB spelling differences, and provides references</li></ul></td></tr><tr><td>US Medical English</td><td><p>Stedman's Medical Dictionary</p><p>Merriam-Webster Online Dictionary</p><p>American Medical Association (AMA) Manual of Style</p></td><td>NA</td></tr><tr><td>GB English</td><td><p>Dorland's Medical Dictionary - medical terminology</p><p>Chambers 21st Century Dictionary - general</p></td><td>NA</td></tr></tbody></table>

{% hint style="success" %}
Oxford English Dictionary spelling is different from British English. A summary of the points of difference can be found at <http://en.wikipedia.org/wiki/Oxford_spelling_>. In those cases where British English and Oxford English Dictionary differ, SNOMED CT follows the British English spelling.

The addition of an Oxford English Dictionary term is allowed but not required. When added, it should be marked as acceptable in the British English dialect. In some cases, it is also accepted or preferred in US English.
{% endhint %}

### Principles for selecting preferred spelling variants <a href="#principles-for-selecting-preferred-spelling-variants" id="principles-for-selecting-preferred-spelling-variants"></a>

SNOMED CT may include (or add) more than one description, each with a different spelling for a given concept. That is, if the above references provide evidence of acceptability in the dialects for which they are being added.

For spelling of preferred terms in a dialect, where the reference sources provide multiple options, a judgment about the most common spelling may be needed. This may be determined by reviewing journal articles containing the word in question.

* Articles should be from highly cited journals, e.g BMJ (for British English) or NEJM or JAMA (for US English).
* For concepts that are not clinical, appropriate scientific journals should be consulted, e.g. Science (US publisher) or Nature (UK publisher).

### Fetal vs. Foetal <a href="#fetal-vs.-foetal" id="fetal-vs.-foetal"></a>

*Fetal* is the preferred term in both the US and GB language reference sets. *Fetal* is acceptable in GB synonyms. Foetal is not acceptable for US language but acceptable for GB language.

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