Both. It's sometimes used in UTF-8 to indicate that the file is encoded in UTF-8 (and not byte order). Personally, I think that software hiding extra unnecess

Both. It's sometimes used in UTF-8 to indicate that the file is encoded in UTF-8 (and not byte order). Personally, I think that software hiding extra unnecessary invisible stuff in my files is really annoying. Some more info here: https://en.wikipedia.org/wiki/Byte_order_mark https://en.wikipedia.org/wiki/Byte_order_mark