The globally recognized unit of measurement for hog casings and sheep casings is called the "Hank":
1 Hank = 100 yards = 91,4 meters
When sorting it is not possbile that 91,4 meters are always supplied precisely, otherwise the calibration or the length per end would suffer. The rule here is that the number of meters varies between 88 and 92 meters. The average of 10 Hanks must be 91,4 meters per "Hank".