There are some special characters which we can use in the XML. thus XML parser will return something like Entity X not defined like errors. this problem comes using ok special characters such as &, > and etc.
Following shoes hoe you can use XML special characters inside the Field values in XML or SharePoint list instance creation.
<Field Name="Value" ><![CDATA[ & ]]></Field>
</Data>you can use any special character inside the CDATA tag.