XML Carriage return encoding
To insert a CR into XML, you need to use its character entity .
This is because compliant XML parsers must, before parsing, translate CRLF and any CR not followed by a LF to a single LF. This behavior is defined in the End-of-Line handling section of the XML 1.0 specification.
xml:space="preserve" has to work for all compliant XML parsers.
However, note that in HTML the line break is just whitespace and NOT a line break (this is represented with the <br /> (X)HTML tag, maybe this is the problem which you are facing.
You can also add and/or to insert CR/LF characters.
A browser isn't going to show you white space reliably. I recommend the Linux 'od' command to see what's really in there. Comforming XML parsers will respect all of the methods you listed.