Forms Data Format

A human user uses Adobe Acrobat or another PDF-editing/viewing application to export the form data in FDF format. (To do this in Adobe Acrobat 6.x for Windows, click Advanced > Forms > Export Forms Data and choose Acrobat FDF Files (*.fdf) for "Save as type." The procedure might be different if you're using another version of Adobe Acrobat.)The FDF file is saved in the company's archives.To look at the form data, a human user would use Adobe Acrobat or some other PDF-viewing/editing application* to open the FDF file; this would cause the PDF-viewing/editing application to 1) find the PDF form from which the form data was exported, 2) load the form data into the form, 3) display the form with the loaded data on the screen.You might be wondering why you'd want to archive an FDF file containing the data for a PDF form instead of simply archiving a uniquely named version of the entire PDF form with the data included in it. There are two reasons:An FDF file containing form data for a PDF form is much smaller than the file containing the PDF form itself, so archiving FDF files requires less storage space than archiving PDF forms.
Some software that people use to view and interact with PDF forms does not allow the user to save a filled-in PDF form. For example, the free "Adobe Reader" software does not allow this. IMPORTANT NOTE TO DEVELOPERS: An FDF file contains the filename and location of the PDF form from which the form data in that particular FDF file was exported. Adobe Acrobat (and any PDF-viewing/editing application that supports PDF forms) relies on that filename and location in order to retrieve and open the appropriate PDF form when opening an FDF file. In other words: when opening an FDF file, a PDF viewing/editing application assumes that the PDF form from which the form data was exported is available at the specified location.Therefore, if you are a developer that is considering implementation of a system that archives FDF data, you'll want to make sure that your system has a reliable method of storing the required PDF forms in known locations. Otherwise, it will not always be possible for PDF-viewing/editing applications to retrieve and open the PDF Forms when they are needed.