To be more clear, if a user is expected to qualify future recordings based on the values of a few variables which identify each show, then those variables and their values should be observable in the EPG.
Otherwise the user is just guessing what to do.
Yeah I agree with that.
They are.
Although deciding which fields to use to prevent duplicates is really driven by the quality and content of the EPG data you use. JRiver isn't a producer of EPG data, and isn't responsible for it. Around the world there are MC installations using many different EPG data sources, many of different quality, so all MC can do is provide the flexibility to choose how you determine duplicates. In my situation in Australia, it is pretty hit and miss, as the broadcasters often change the description of programs when they are repeats, they almost never flag a program as a repeat, and they will often only provide the series name and not the episode name for repeats.
What you will need to do is become familiar with the quality of your EPG source, and decide for yourself which fields to use.
Anyway, if the data exists in your EPG source, then you can see it in MC, in the Guide and the Guide "details" screen, which is the screen shown when you click on a program in the Guide with a mouse, press enter with a program highlighted, or press the OK button on a remote with the program highlighted. Just to confirm, the fields MC offers to determine if a program is a duplicate are [Name], [Series], [Description], [Season], and [Episode].
Assuming that the Series and Episode names are available, they are shown in the Guide, in the format [Series]:[Name] (where [Name] is the Episode name, as I posted earlier) both on the Guide program bar and at the bottom of the Guide when the program is highlighted.
The Description is always shown at the bottom of the Guide screen, for the highlighted program.
If the Season and Episode numbers are available they are shown in the Guide detail screen, in the format [Season].[Episode] as per the attached image. The [Series]:[Name], and [Description] are also shown on that detail screen, along with the Start Time, Channel, Duration, etc., depending on what is in the EPG data. As the program hasn't been recorded yet, MC hasn't done a "Get Movie & TV Info" lookup on it yet, so it won't have the additional metadata that may come from TheTVDB, just what was in the EPG data.
So in order to avoid recording duplicates, you need to know what data is likely to be available for the program you are recording with a recording rule, and how reliable it is going to be.
If the [Series] (name), [Season] and [Episode] (which are numbers) fields are
always available, then using those fields
only to identify duplicates is the very best solution. For a TV series that is.
For a documentary, the [Name] is probably the best field to use, as often that is included accurately in the EPG data. In a David Attenborough documentary series, which typically has both the <title> and <sub-title> fields in the EPG data, which become [Series] and [Name] respectively, I would use those two fields, [Series] and [Name].
There probably aren't many programs where I would use [Description] in determining if a program was a duplicate, because broadcasters often add prefixes and sometimes suffixes to the program description.
As far as I know, all fields use an exact match to determine if they are the same for identifying duplicates. So even a minor change will make the program unique as far as MC is concerned. I don't think MC does any "fuzzy logic" lookups to match programs that have similar, but slightly different EPG data.
Then there is one final gotcha:
If the "Get Movie & TV Info" lookup MC does after a program is recorded changes any of the fields you are using to identify duplicates, perhaps to correct the Series or Episode name, then you will no longer get a match on a duplicate. However, as the TheTVDB lookup relies on the same fields as the duplicate lookup, it is likely that the "Get Movie & TV Info" lookup won't find a match to change the fields anyway. The "Get Movie & TV Info" lookup uses [Series], [Season] and [Episode] to lookup TheTVDB.
Note: Anything in square brackets [] is a field name in MC. Anything is round brackets () is a description of what I am talking about.
Finally, I can think of some improvements to the existing process and functionality, but if the above isn't good enough, how would you do it differently? What do you expect MC to do?