What is the FDF file and which application opens it?
An Acrobat Forms Data Format (FDF) file contains only the data needed to fill in a standard PDF form, so it’s smaller in size and, therefore, more efficient. When you launch a FDF file, Acrobat Reader will launch the external PDF form reference embedded within the FDF file. It will direct your default browser to access the PDF form and fill it in with the FDF data.
