Umm ... did we make Harry Potter unintentional getting crap past the radar? Yep, spelling. As a general rule, words ending in -or in American English end in -our in British English. American 'Fetus' is equivalent to British 'foetus'. Words ending in -ed in America may or may not end in -nt. Learned becomes learnt. Dreamed becomes Dreamt. Here. Also, no-one goes to a wedding in vests and pants - that's underwear.