zlacker

Data point: I am American and I would not spell 'cancelled' any other way. I don't think it is strictly British.

>>jchw+(OP)
As far as I've seen, Americans are just plain inconsistent on this spelling.

Cancelled has nice pairing with cancellation, canceled can be typed nicely without any repeated finger use on qwerty, both clearly mean the same thing and aren't confused with something else... I say let the battles begin, and may the best speling win.

Referer pains me though.

>>Groxx+ai
To be fair, "referer" is just a misspelling, I don't think it was ever accepted as a correct spelling by a large number of people. I'm sure you know the backstory though.