BOM是否用于2字节Unicode文本文件？

Question

我知道BOM表用于UTF-8文件，但是对于每个字符为2个字节的文本文件呢，我也应该在其上添加字节顺序标记吗？

Answer 1

BOM's were invented for UCS-2 and UTF-16, and then only later appropriated by Microsoft (and then XML) for UTF-8. Think about the name: 'byte order mark'. UTF-8 has only one possible byte order, so it doesn't need a BOM to reveal the order. The three-byte sequence for U+FEFF in UTF-8 has, instead, become a Unicode signature for file type sniffing.

However, early versions of the XML support in Java did not respond well to a UTF-8 BOM, in spite of the inclusion of the UTF-8 BOM in the XML standard. Further, a file with a BOM can't be simply concatenated onto another file, because U+FEFF isn't BOM in the middle of the file; it's ZWNBSP.