The Zippo Code

From mid-1955 Zippo started year coding their lighters by the use of dots (.). From 1966 until 1973 the year code was denoted by combinations of vertical lines (). From 1974 until 1981 the coding comprised combinations of forward slashes (/), and from 1982 until June 1986 the coding was by backslash (\).
In July 1986, Zippo began including a lot code on all lighters showing the month and year of production. On the left of the underside was stamped a letter A–L, denoting the month (A = January, B = February, etc). On the right was a Roman numeral which denoted the year, beginning with II in 1986. Thus a Zippo stamped H IX was made in August, 1993. However in 2000, Zippo altered this system, changing the Roman numerals to more conventional Arabic numerals. Thus a Zippo made in August 2004 was stamped H 04. There was a myth that Zippo lighters were made by prisoners, and the number identified the prisoner, or their crime and sentence length. Another myth was that a Zippo stamped 'H' was inferior to one stamped 'A'.