I notice there are archetypes whose ids are spelled using both systems, e.g. fetal_biometry and foetal_growth. This makes life somewhat annoying for naive search tools that don’t know how to abstract away such differences.
Is there a policy on standardising to a particular form of English? Terms like ‘fetal’ might not necessarily be regarded as just US, but perhaps just the ‘modern’ way to spell the word. ‘Paediatric’ also comes to mind. My impression is that in the UK, docs are likely to write ‘fetal’ but ‘paediatric’.
So the policy should at a minimum just define which form of any given term is to be used, so that at least, all foetal-related archetypes are spelled ‘fetal’ or ‘foetal’ but not both.
The alternative spellings should be in the keywords for the archetype.
You’re right that there is some variability wrt the spelling norms used in various places in archetypes. There also isn’t a written policy on spelling norms within archetypes, although we tend to use British-like spelling in most cases (for example specialisation vs spesialization). This should possibly be put in the Archetype content & style guide.
The discrepancies are probably also a result of the fact that a significant number of archetypes have been edited by people whose first language isn’t English.