Variations within an edition, which are made prior to publication; can include:
• alterations due to stop-press insertions, damaged type, etc.
• the addition of errata leaves, advertisements.
• textual changes affecting page lay-out.
• some special-paper copies.
This term applies only in connection with the printed pages, and not variations in bindings. (e.g.: a small number of copies of Ernest Hemingway’s For Whom the Bell Tolls were erroneously printed without the photographer’s credit on the back of the dust jacket. The presses were stopped midway through the first run, the credit was added, and the second state of the first edition resulted.)