Needless to say, there are many more varieties of English than just those spoken in the United Kingdom and the United States; indeed, each of those countries is home to multiple dialects. Nevertheless, for the purposes of an English-language style guide, a comparison of the 'standard' dialects of these two extensively used varieties can be instructive.

Of course, entire books have been devoted to the differences between BrE and AmE conventions with regard to spelling, vocabulary, punctuation and grammar. An exhaustive accounting thus falls well beyond the scope of this guide. Nevertheless, because, unless otherwise explicitly specified, the UOC prefers that the texts it publishes be written in BrE, this section has been included as a quick reference guide to some of the most common differences.