[johnke]

There were also some examples of sloppy editing in the updated edition, like multiple uses of the word "perimetre" which the author acknowledges was an 'incautious find-and-replace from the US English "meter" to UK English "metre"' https://qntm.org/antimemetics#komment6913d2eb6c240

[ethmarks]

Which is especially odd because the author (Sam Hughes) lives in the UK and wrote the original in UK English, but apparently wrote the rewrite in US English. For example, a chapter in the original was titled "Case Colourless Green", but in the US edition of the rewrite that chapter is "Case Colorless Green" (without the 'u'). So Hughes, a native UK English speaker, wrote the rewrite in a non-native (to him) dialect, then had it (lazily) translated into his native dialect.

[rtkwe]

It was probably to deal with the transposition [0] out of the SCP universe into a new one. SCP is vaguely 'set' in the US because that's how a majority of the contributors naturally write and spell things, which sets the voice of the world indirectly.

[0] AKA "filing the serial numbers off" when it's explicitly fanfiction instead of a shared universe model like SCP