The choice of character for the BOM isn't weird or random - it's a zero-width no-break space, which means it's supposed to be invisible even when your software

The choice of character for the BOM isn't weird or random - it's a zero-width no-break space, which means it's supposed to be invisible even when your software is capable of displaying it. If you remove whitespace from the beginning and end of your keys you'll be fine. It seems arbitrary, but I don't think they could have made a better choice.