UTF8BOM

UTF8BOM refers to the Byte Order Mark (BOM) when used with UTF-8 encoding. The BOM is a special character, represented by the Unicode code point U+FEFF, that can be placed at the beginning of a text file to indicate its encoding. For UTF-8, the BOM is represented by the byte sequence EF BB BF.

While the BOM is commonly used with UTF-16 and UTF-32 encodings to signify byte order (endianness), its use with UTF-8 is generally considered optional and often discouraged. UTF-8 is a variable-width encoding and is byte-order independent, meaning the BOM does not convey any byte order information in this context.

The primary purpose of the UTF-8 BOM is to signal that the file is encoded using UTF-8. However, many applications and parsers, especially older ones or those not specifically designed to handle UTF-8, may misinterpret the BOM as regular text. This can lead to display errors or parsing issues, as the BOM character is not a printable character in most contexts.

Consequently, many systems and developers prefer to omit the UTF-8 BOM to ensure broader compatibility. Instead, they rely on other mechanisms to determine file encoding, such as file extensions, content sniffing, or explicit metadata. When the BOM is present, it's crucial for software to recognize and handle it correctly to avoid problems. Some editors allow users to choose whether to include or exclude the UTF-8 BOM when saving files.