I assume that NCR is for National Cash Register, AV is for Avaya, VZ is for Verizon, Q is for Qwest, BLS is for BellSouth, and LU is for Lucent. (Am I correct?)
But, pray tell, what do the stock codes ACR, T, CMCSA, VOD stand for? And if they aren't "obvious" entities, how would they relate to the (old) AT&T "Bell System"?
Also, AT&T used to own a part of Bell Canada, which is now part of Bell Canada Enterprises. I don't know if Nortel is now an entity totally separate from Bell Canada (in the way that Lucent is now separate from AT&T), but Nortel was once Northern Electric, and also a "part" of the "Bell System" in a way. Both Bell Canada (partially owned by AT&T) and Western Electric (totally owned by AT&T) were part owned Northern Electric back then.
Southern New England Telephone Company (for most of Connecticut) was only partially owned by AT&T, and became a separate entity altogather with 1984. But in 1997, SBC (which had just taken over Pacific Telesis' Pacific Bell and Nevada Bell) took over SNET. And now, SBC has been renamed "at&t" with their purchase of AT&T.
But I think that Cincinnati Bell is still a separate entity altogather. Prior to 1984, AT&T only partially held Cincinnati Bell, but with 1984, it became a totally separate company of its own. But it was still a "part" of the old Bell System, to some degree.
So, shouldn't Nortel, Bell Canada Enterprises, and Cincinnati Bell also be included as "leftovers" in what had once been the old AT&T "Bell System" as well?