Yes I know there is no difference in the company's cusip, what I was thinking, used for in house tracking, as we know the shares in broker name and he may use that F009417 to keep retirement accounts separated from regular accounts?
That is giving the brokers the benefit of the doubt, however not to say you are not 100% correct, that they are using as you say, "avoid short interest reporting" could very well be, it would be great to get feed back from those that have this #F009417 in their accounts.