XML Reference: Siebel eBusiness Application Integration Volume V > Overview >
Special Characters in XML Documents
Special characters should be represented in accordance with XML standards for those characters in order for them to be correctly interpreted within Siebel applications. Also, specify the character set you are using if it is not UTF-8 (the default).
NOTE: To edit an XML document including binary or encoded data, use editors such as Notepad or Word that do not convert the data upon saving the file.