Doug Brott said:
To get into the habit of confusing people

.. The good news is that eventually they will ALL be (c) and (s) which help us humans distinguish it even better
Actually, this is a bit of an insight into the programming effort/staff on the DirecTV HD receivers/dvr's, or lack thereof.
Really, if the actual programmers (or their management/designers, take your pick) can't get something THIS SIMPLE straight, it does not bode well for the entire program.
To be sure, it's a 'simple' thing (both from the users and the programmers standpoint), but if I had a dollar for every time this question gets asked here (the original one, 'I see for them is 99a, 99b & 103a,103b. What are the c's and any idea why I don't see them?'), I could pay my internet charges for a month. And then the next batch of similar questions next month could pay for my next months bills, ad infinitum.
As I did tons of consulting to major companies on programming problems over my career, I think that the problems are pretty apparent, despite having a fairly good product (after what, some two years of fairly continual improvements).
Either the 'small stuff' is being ignored, or, like I said, it's a bad omen. I made tons (enough to take a very early retirement) from folks who at least realized that their efforts were being either sidetracked or deep-sixed.
Actually, I await a news release at some point that DirecTV brings in some independent consultants to tighten up their process. But perhaps that's already been done, and it hasn't been released/talked about yet (Re: TIVO). Simply don't know.