For XML files, the syntax of Data Items can be as follows: 

Static Values

You can indicate that an Item should always evaluate to a specific value by prefixing that value with "0,"

Dynamic values

You can also use the internal XPath expression evaluator to pull in data from the file dynamically.

Given the XML data: 

You can pull in information by specifying the XML Node using XPath expressions. 

Given the XML data: 

You can pull in information by specifying the XML node using XPath expressions, separating the node from the property with the '$' character. 

Given the XML data: 

You can use a conditional XPath expression. 

Given the XML data: 

XML fields may also be concatenated by separating the values with a comma. If one or more XPath expressions need to be combined with static data, surround the static data with quotes.