PDF (adobe.com)

Recognizing template-based documents in Design view

In a document based on a template (a template-based document), editable regions appear in the Design view of the Document window surrounded by rectangular outlines in a preset highlight color. A small tab appears at the upper-left corner of each region, showing the name of the region.

In addition to the editable-region outlines, the entire page is surrounded by a different-colored outline, with a tab in the upper-right corner giving the name of the template that the document is based on. This highlighted rectangle reminds you that the document is based on a template and that you can’t change content outside the editable regions.