Textual Content [XML Standards]
Because of its support for the Unicode character set, XML supports a range of characters, including letters, digits, punctuation, and symbols. Most control characters and Unicode compatibility characters are not allowed. For a complete list of character classes, see Appendix B of the XML specification.
Because XML relies on <, >, and & to delimit markup, you should represent these characters using the character and entity references described in the following topic, or confine them to CDATA sections.