Replacement Note - A replacement banknote is a banknote that is printed to replace a faulty or damaged note and is used as a control mechanism for governments or monetary authorities to know the exact number of banknotes being printed. Also, since no two serial numbers can be the same, the bill is simply reprinted with a symbol in the serial number, identifying it as a replacement for an error note. Replacement bills have different symbols to mark the error around the world, although the most popular examples are "star notes."
Silver Certificate - A bill formerly issued as legal tender by the US government backed by and exchangeable for its value in silver bullion. This type of representative money was issued between 1878 and 1964 in the United States as part of its circulation of paper currency.
Gold Certificate -The gold certificate was used from 1863 to 1933 in the United States as a form of paper currency. Each certificate gave its holder title to a corresponding amount of gold coin established by the Coinage Act of 1834. Therefore, this type of paper currency was intended to represent actual gold coinage. In 1933 the practice of redeeming these notes for gold coins was ended by the U.S. government and until 1964 it was actually illegal to possess these notes (In 1964 these restrictions were lifted, primarily to allow collectors to own examples legally; however the issue technically converted to standard legal tender with no connection to gold).
National Currency - National Bank Notes were United States currency banknotes issued between 1863 and 1935 by National banks chartered by the United States Government. The notes were usually backed by United States bonds which the bank deposited with the United States Treasury. In addition, banks were required to maintain a redemption fund amounting to five percent of any outstanding note balance, in gold or "lawful money."
Federal Reserve - Federal Reserve Notes, also United States banknotes or U.S. banknotes, are the banknotes used in the United States of America. Denominated in United States dollars, Federal Reserve Notes are printed by the United States Bureau of Engraving and Printing on paper made by Crane & Co. of Dalton, Massachusetts.