well, it will work for every prefix, not just SBS, i.e. SBA36xx
is the same as SBA98xx, and so on.
the math = 12 * thousandth place + 2 * hundredth + 11 * tens + 1 *
ones
so u can count from there.... the diff between 98xx and 36xx is
(6*12+2*2), which is 76. the fact that it is a multiple of 19 means
you will get the same suffix.