The HTML includes field tags such as ‘Address (Street, City, Province, Postal code)<br>{% text_field “submitted_address”, class:“text” %}’ . The reference page at http://nationbuilder.com/petition_signature_variables has a link to “signup” variables, which have many options. This leads me to believe that it “should” be possible to add any of those fields. If not, I would think that this would be a fairly simple feature improvement.