WCF/PHP - XML Parser can't handle HTML entities?

[immereict]

My RESTful WCF service accepts XML request bodies from clients, most clients are PHP applications.The PHP applications encode their requests with htmlentities(), which is placed within the element tags. For example, a request to add a new user-account might look like this:\[code\]$body = "<user> <userName>" . htmlentities( $userName ) . "</userName></user>"\[/code\]The system works fine, there have been zero errors with it, until today.I looked through the logs and saw this request had failed:\[code\]<user> <userName>&egrave;eesu</userName></user>\[/code\]with the following exceptions:InvalidOperationException: "There is an error in XML document (4, 12)."XmlException: "Character reference not valid. Line 4, position 12."(where line 4, position 12, refers to the \[code\]<userName>\[/code\] element's InnerText (i.e. the string \[code\]&egrave;eesu;\[/code\]).\[code\]&egrave;\[/code\] is a valid HTML entity, but I understand that XML only defines a minimum set of character references (\[code\]&\[/code\], \[code\]<\[/code\], etc), and that XML expects all other characters to be in their document encoding representation instead, and so will reject things like \[code\]&egrave;\[/code\].Can someone confirm this is the case? And if so, how can I get PHP to only encode XML-specific entities instead of HTML entities?