Could a letter block be valuable in any way, like AF 0123456789 Q. The "Q" being unusual, or a "Y" or "Z" for example? Just wanted to know!
Certain Letter Blocks are indeed collectable, especially in the $1.00 Silver Certificates, and Federal Reserve Notes. Not only limited to $1.00, though. The letters themselves (Q, X, Z) are not rare. The value involves when and where a number ends, and how many of that letter block are involved in a series. If a Federal Reserve Bank Series 2005 F00001234B $1.00 Fed note is the last one printed before series 2006, then there will only be 1234 of that block printed (FxxxxxxxxxB) It will be a rare block., as opposed to the FxxxxxxxA block before it,which will have all 99,999,999 printed.