-- Randal L. Schwartz, Perl hacker

That's a proper subset of UTF-8, so not really necessary. Can a particular XML file be represented in, say, 8859-6 or JIS-X, and still be standard? I don't like this because it means that a file can't be read unless the parser knows that character set.

7-bit ISO-8859-1 (also called "ASCII" {grin}) is a proper subset of UTF-8, but not 8-bit ISO-8859-1. So yes, you'd need to declare the file as ISO-8859-1 if you wanted to have any "second half" characters, but otherwise you can let it default to UTF-8.

-- Randal L. Schwartz, Perl hacker

Actually XML uses UTF-8 or UTF-16 by default (and has ways to figure out which one is used), but allows any encoding, as long as it is specified in the XML declaration (as <?xml version="1.0" encoding="whatever"?>). The parser then has to deal with the encoding.

It is an implementation choice in expat (and then in XML::Parser) that all strings are passed to the handlers in UTF-8, but I don't think the XML spec mandates this choice.

And because the environment in which the XML is used often does not support UTF-8, but rather latin 1 or shift-JIS or whatever it is often very important (and painful!) to convert all strings back to their original encoding.