I hope it's okay to post this here. If not, feel free to delete it.
English is not my first language, and I know that there are other authors here who are only second language English speakers, or even third. To these people, I know it can be very dificult to be sure of which spelling to use when writing in American, British or any other form of English. I know there are differences when it comes to Canadian and Australian as well, but I'm not very familliar with these differences and so will not go into them.
I figured this thread could act as a reference to people who are uncertain of which sort of spelling to use. I know MNFF allows both American and British (and any other official form you can think of) as long as it's consistent. No mixing them up, in other words.
Being a language geek, and particularly an English geek, I have studied these differences rather thuroughly during my reading and writing "career". I'll start this thread off with some basic differences:
S vs. Z
A lot of places where the letter Z is used in American English, the British form uses S. This includes words like realize/realise, characterize/characterise, etc. Basically any word that ends in -ize/-ise.
The Letter U
In British English one uses the letter U in a lot of words where this letter is usually left out in American. These are words such as colour/color and favour/favor. Colour and favour are British forms, whereas color and favor are American.
-er or -re
In American English one has, for rather understandable reasons, switched around the last two letters of certain words, more specifically some words that end in -re in British English. The British theatre, metre and centre become theater, meter and center.
These are the most immediate differences I could think of. I was thinking that if people have questions regarding words they're uncertain about the spelling of in American or British English, they could ask here. Hope I'm not out of line in creating this thread.