Ooh, yes, I'd not noticed that proprerty of JSON, but you're right! Very useful. There's similar tedious description of that technique with the "<?xm" in the XML spec. Amazingly, at least a year ago, nobody seemed to have implemented the relevant DWIM filter [from InputStream (octet sequence) to Reader (character sequence)] for Java for XML, and I've not been able to convince people that implementing that would be a productive use of my time. So we all arse around with character set objects and get it wrong, :(.