Originally Posted by sharkster
I honestly have a hard time even understanding it because you can have an SP for 'new only' and the shows are not listed as new in any way, yet it will pick up every airing, even though it doesn't have a 'new' attached to it AND it has an OAD that is also not new.
The TiVo looks for specific things in the Guide Data to determine what to do. Not all of these things are human-readable, nor does it use some of the information which is displayed for the benefit of the user.
There's a flag (not necessarily visible by us viewers) called IsEpisode -- if it is set to YES then the TiVo knows that the Guide Data is for a specific episode, and it can look at the OAD and apply all the rules about whether or not the show should be recorded.
If the flag is not there, it knows that the data is generic. The default seems to be, if the Guide Data doesn't refer to a specific episode, it records the episode anyway, in case it might be
new. This is probably also the case when other parts of the Guide Data is missing (like ThAbtO said in post #2 of this thread).
Whether a show has a "R" or not in the visible Guide Data doesn't matter -- the algorithm doesn't look for that.
With older TiVos, there are backdoor codes which reveal some of the hidden Guide Data. (Maybe for the newer ones, too, but I haven't been keeping up with that part of the forum.)