Merge pull request #238 from xml-project/fix-cast-content-type

Stating that XPath format is default for JSON->XML

steps/src/main/xml/steps/cast-content-type.xml

@@ -58,12 +58,10 @@ model document into XML is
 
 <listitem>
 <para>Casting from a JSON media type to an XML media type, converts the
-JSON into XML. <impl>The precise nature of the conversion from JSON to XML
-is <glossterm>implementation-defined</glossterm>.</impl>
-If the input document is a text node or other string representation,
-implementations <rfc2119>should</rfc2119> use <function>fn:json-to-xml</function>
-by default.
-</para>
+JSON into XML. An implementation <rfc2119>must</rfc2119> support the format
+specified in section “XML Representation of JSON” of <biblioref linkend="xpath31-functions"/>
+as default for the resulting XML. <impl>It is <glossterm>implementation defined</glossterm> whether
+other result formats are supported.</impl></para>
 </listitem>
 
 <listitem>