Don't know if it fits/fit (UK English/US English - subject of a previous post) the criteria, but what about "zed" & "zee" for the 26th letter? (which was going to be the subject of a future stales post).

In terms of pronunciation without a spelling change, UK, Australian, NZ & South African English inevitably uses "m-air" whereas US (& Canadian??) English uses the OE "may-or" for the word mayor.

stales