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

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.

References for Spelling


US-GB differences

Wikipedia, the free encyclopedia*

*Note: Wikipedia may be used as a starting point, or source, for authoritative references, but not as an actual reference

  • First point of reference
  • Provides a summary for authors, addresses many US-GB spelling differences, and provides references
US Medical English

Stedman's Medical Dictionary

Merriam-Webster Online Dictionary

American Medical Association (AMA) Manual of Style

GB English

Dorland's Medical Dictionary - medical terminology

Chambers 21st Century Dictionary - general


Oxford English Dictionary spelling is different from British English. A summary of the points of difference can be found at 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.

Principles for selecting preferred spelling variants

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

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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