Fr. 2074-F. 1981A $20 Federal Reserve Note. Atlanta. PMG About Uncirculated 55. Obstructed Printing Error.Retained Obstruction Errors such as this are one of the most popular Small Size error types. A paper fragment which at first glance does not appear to be currency paper fell atop the sheet prior to the First Printing and remained there likely adhered from the pressure applied by the printing plates. It more than likely dislodged when the note was paid out and folded in half as the retained fragment exhibits a fold as well. Just a great error with an even better look to it. Worthy of inclusion in the finest collection of US currency errors.