In Finland, in informal correspondence over email in English I often see the acronym "BR" or "Br" used in the signature before the name, and I've seen some people from at least Germany do the same. I believe this is an acronym for "Best Regards", but many acronym lists omit it. 1
How widely used / understood is this acronym? Are there specific geographical regions where it's common? Does usage of it in a signature stand out as weird for some audiences?