...

The wizard displays the fields from your form. Only controls that are considered form data will be listed. For Example, the link, signature, image, upload, trigger, section, PageBreak and video controls will not show up as available fields in the saved or key field lists as there is no value to save or query against.

...

The same name fields will be categorized in the data tab of the form submission like this:

Signature controls are excluded from Saved and Key Field lists.

Error Page

If you supply a Url in this property field,  will display this page whenever it fails to load a default document from one of the form's Document URI Read methods and also when it fails on a document URI Write method. If this field is not set a default error page will be displayed.

...