What are invalid characters in XML

Question

I am working with some XML that holds strings like:

This is a string

Some of the strings that I am passing to the

Answer 1

The list of valid characters is in the XML specification:

Char       ::=      #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]  /* any Unicode character, excluding the surrogate blocks, FFFE, and FFFF. */