Append to Existing File

  You can append one or more sections, or an entire book to an
  existing text file.  This feature is not available for PostScript
  files.  Select the Text button in the Print Format box to enable
  this feature.

  Click on the text-entry field, erase the default name, and en-
  ter the name of the existing file.  Then click on the Append to
  Existing File button.