The tale tells that Arthur B. Laffer sketched his famous curve on a napkin during a lunch with Jude Wanniski, Donald Rumsfeld and Dick Cheney. At that time, he surely did not imagine the renown that will follow this day of December 1974. The Laffer curve relates for each tax rate the expected total tax revenues. For low rates, tax rate and tax revenues move in the same way. But, as rates increase, this relation works in the opposite direction: higher tax rate produces smaller tax revenues. Hence, beyond this "maximum tax rate" the disincentive" effect of taxation is overwhelming. Nonetheless, this maximum rate is not empirically defined: it depends on place, time, circumstances, etc. The following file does not pretend to be exhaustive. Its goal is to introduce key arguments about Laffer Curve.