This is quite cool. I haven't heard of this until I discovered an eBay listing for this note: http://www.ebay.com/itm/1999-1-00-S...attern-BLACKOUT-NOTE-PCGS-AU-50-/111131240043
I just wonder how the heck a test sheet like this would make it into circulation, unless BEP employees wanted to take one home! Not an easy thing to do in 1999, like it was in the early 20th century and prior.