This lets the user upload files directly from the data form. It is displayed as a link to the file.
Files are not uploaded to the same page. Instead, a separate page is created for each file in a different category, 'file' by default, with the pagename being the name of the image.
[[form]] fields: document: type: file label: Upload document category: alternative-category [[/form]]
The specific properties you can use on a file field:
Note that images won't be treated like they are when attaching an image to simple (i.e. non-data form enabled) page. This means they won't be displayed by the [[gallery]] tag.