Harley-Talk.com

Beginning in 1920 a team of farm boys down South that would become known as the “hog boys” consistently won races. The group had a hog, or pig as their mascot. Following a win, they would put the pig (a real one) on the back of their Harley and take a victory lap.[26] In 1983, an organization was formed, taking advantage of the long-standing nickname by turning “hog” into the acronym H.O.G., for Harley Owners Group. Many Harley-Davidson enthusiasts capitalize the word to make “Hog” and consider this term the sole property of H-D.

Harley-Davidson attempted to trademark “hog,” but in 1999 ultimately lost the case, with the appellate panel ruling that “hog” had become a generic term for large motorcycles, and is therefore unprotectable as a trademark.[27]

On August 15, 2006, Harley Davidson Inc. had its NYSE ticker symbol changed from HDI to HOG.