Earlier this week, I had a message via SOL from "Richard" (with a .au reply addy), in reply to Chapter 28 asking about my use of "Mom" rather than "Mum".
I've tried to reply, but the message has bounced back as being from a domain that doesn't exist. It's a non-sensitive reply from me, so Richard, if you're reading, here it is.
This is an interesting one. I've been English my whole life (well, Doh!) and I've always called my mother "Mom". I know the reference books all refer to "Mum" as English and "Mom" as American, but, in reality, it varies from area to area. There are large portions of the country that use "Mam" (South Wales, for example).
Add to that, contemporary youth culture in the UK is heavily influenced by movies, TV and music imported from across the pond. Sure, it's still distinctively British, but more and more "American" words are slipping into the language.
It's something that the 'purists' get upset over, while the rest of us just get on with things.
hope that offers some sort of explanation.