European Copies: US Spellings When Writing Letters?

[AnimalCrossingPerson]

I'm well aware that when writing letters to villagers, the response is generally based off of how long the letter is and that for the most part they don't know any definitions. However, words that aren't in the list generally don't help, so my question is: are both US and UK spellings in the list or just one or the other?

The game has had its localisation but for some reason that just consists of removing some events and renaming a couple items rather than changing anything else such as "catalog" to "catalogue".