I just purchased this very cool 1986 $5 Bird Series Fold Error.
The paper fold occurred before the note was printed resulting in an extra piece attached to the note and a blank area on the back of the note. When the fold is opened a piece of the reverse printing appears on the front along with a portion of the right serial number.
I will post better pictures once the actual note arrives and I can scan it myself.
{http://www.davgro.com/images/cpmf/1986_$5_Fold1.jpg} {http://www.davgro.com/images/cpmf/1986_$5_Fold2.jpg}
{http://www.davgro.com/images/cpmf/1986_$5_Fold3.jpg}