IDIS again

Here is the paragraph first:




Apparently, the CIA's files under this program contain the names of some 9,900 plus Americans. In response to a question from LHS referring to the New York Tiles stories about the "files on 10,000 Americans," Colby indicates that the CIA's "9,900 names" is not the same as the IDIS master subject index described in the december 30, 1974 memorandum from LHS to Philip E.Areeda, Counsel to the President



I'm really pissed of looking for this IDIS !!! can you please help me? I found many possibilities and I'm not sure what is the exact one.. I've already posted something about this IDS but I didn't get enough explanations.. Yes another problem is about "9900 plus" does it mean more than 9900 ?? or what ??

Thanks a lot !