Only absolute telling differences is on the 1883 the first issues didn't have the word "CENTS" on reverse and the 1912 was the only year with mintmarks D/S under dot to left of CENTS. Key Dates=1885,1886 & 1912S...Semi-key dates are 1884,1887, 1888 & 1894. All others are common and can be had for $.50 each.