I think with this company it's probably political: a worldwide sales and marketing force does not particularly like having U.S. grammar (and, probably more importantly, the U.S. system of weights and measures; metric system is listed only parenthetically) imposed upon them as standard by the corporate head office. Therefore, they have apparently declared themselves unwilling to use the A4-sized documents prepared for them by the head office until and unless those documents are delivered in UK English.

I can't really say I blame them, and I honestly don't mind doing their conversions for them -- but I do wish they would go the extra mile (kilometre) and supply me with a list of the conversions they would like me to implement. Really, it's awfully hard for me to know exactly what they want. And because, as I've said, I'm preparing a corporate style guide, this would be a very good time to have the conversion process completely documented. Ah, well...