DataPath: Filters that stop a discovered value from being considered an instance of the respective property

[baltpeter]

Sometimes, a tracker will transmit something like idfa: none. Currently, this would be detected as an IDFA transmission, which is obviously wrong.

I think we'll need filters to prevent that. Maybe it's easiest if we can either specify a positive (onlyIf: \d+) or negative (notIf: none) regex?

[baltpeter]

One question we still have to discuss: Do we want to filter out transmissions like idfa: 00000000-0000-0000-0000-000000000000? For my research, I always considered them as IDFA transmissions since the app/tracker was clearly trying to transmit this information but just happened to not succeed because the OS blocked it.

But in the context of TrackHAR, I'm leaning towards a stricter definition of a transmission. Legally speaking, I'm not sure whether trying (and failing) to read information from a user's device would trigger Art. 5(3) ePD. But in any case, we cannot claim that an ID was transmitted if the "ID" was just zeros. And we do always say that we would rather under- than overmatch.