A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows ...

Now click the icon showing the dog-eared page with the Excel logo on it. The code & [File] should appear. Now click OK. The file name will appear in the header when you print the file.

Also known as a Comma Separated Value file, a comma delimited file is a standard file type that a number of different data-manipulation programs can read and understand, including Microsoft Excel.