Characters Not Allowed in XML

Feedback for TMX 2.0 proposal, with relation to XLIFF:

TMX documents may have to store text that content characters not allowed in an XML document (e.g. some control characters).

The draft of TMX 2.0 has no provision on how to work around this issue, (which, in my experience, occurs a lot more often than the
PUA characters perceived problem).

While I do not have a solution to propose at this time, I believe it would be helpful to have one and it should be the same for both
TMX 2.0 and XLIFF 2.0.

-ys