As a Brit my natural tendency is obviously to go with British English but I was just editing the Webform tag excerpt and I was torn between using "personalised", or "personalized". The latter is already included in the main tag wiki so I didn't know whether to change both to British, change both to American, or leave the one that's already there alone and updated just the excerpt to use British English.
I know it's of very little importance but are there any official Stack Exchange guidelines on this?