This is the ".form/pagearea" template. It should be called in the following format:

{{.form/pagearea
|htmlid=id to use for the pagearea and as a prefix on each display item
|title=name of pagearea, as used in generated text 
|css=directives to include
|template=name of "for template" - default=Page area
|embed in field=name of field to embed template calls in, eg <code>.page[header]</code>
|widgets=name of a non-empty array of widget namespace objects
|queries=name of a non-empty array of query templates 
}}

Edit the page to see the template text.