<P> Current Zippos carry a suggested retail price between US $14.95 and US $11,893.95 (for the 18k solid gold model). In 2001, according to the fall 2003 issue of IUP Magazine, a 1933 model was purchased for $18,000 at a swap meet in Tokyo, and in 2002 the company bought one valued at $12,000 for its own collection . During the 2007 75th anniversary celebrations, Zippo sold a near mint 1933 model for $37,000 . </P> <P> All Zippo windproof lighters carry an unlimited lifetime guarantee, promoted using the trademarked phrase "It works or we fix it for free ." The corporate web site boasts: "in almost 75 years, no one has ever spent a cent on the mechanical repair of a Zippo lighter regardless of the lighter's age or condition ." </P> <P> In 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 . In 1979 an error was inadvertently introduced into fabrication, with some lighters reading / on the left and / / on the right instead of / / on the left and / on the right, but was fixed within the year . From 1982 until June 1986 the coding was by backslash . </P> <P> After July 1986, Zippo began including a date 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, C = March, etc .). On the right was a Roman numeral which denoted the year, beginning with II in 1986 . However, in 2001, Zippo altered this system, changing the Roman numerals to more conventional Arabic numerals . Thus a Zippo made in August 2004 was stamped H 04 . </P>

What do the marks on a zippo mean