The Standard Catalog of World Paper Money is a very well-known catalogue of banknotes that is published by Krause Publications in three volumes. A banknote (often known as a bill, paper money or simply a note) is a kind of Negotiable instrument, a Promissory note made by a Krause Publications is a publisher of Leisure -time magazines and books These catalogues are commonly known in the numismatic trade as the Pick catalogues, as the numbering system was originally compiled by Albert Pick. Albert Pick (born 15 May 1922 Cologne) is a retired German numismatist.
The numbering system uses capital letters (e. g. 'P', 'PS', 'PM') and an integer to identify a note. If a note has signature or date variants, then a lower case letter follows. (e. g. P120a).
The sorting of notes is usually by series/date, then by denomination.
Regular variants start with the letter a, b, c, . . . Error notes usually bears the letter x, while specimen notes have the letter s. Unissued remainders (sometimes incomplete printings) have the letter r, while known replacements would also have the letter r.
This is updated every two or three years, currently in the 11th edition.
This is updated annually. Currently in the 14th edition.
This is updated every three or four years, currently in the 10th edition.