Prior to April 1991, and the implementation of work sharing dropship discounts for 3rd Class (Standard A) mail, virtually 100% of the commodities transported by Fairrington were classified as general commodities. A general commodity is anything that moves in commerce with the exception of those in bulk, exempt, and household goods. This is a vast array of items that vary in value, cubic dimension and weight. This diversity, along with distance sensitivity (rate basis number), is how tariff charges are calculated. A successful general commodities program was initiated by cloning the formula that was developed for the insert portion of Fairrington's business.