Apple has used Data Detectors for a really long time. A Data Detector is that little dropdown arrow that appears over a calendar date, phone number, etc. when it appears in Apple Mail for instance. I just discovered that there is a hidden (so far) Data Detector in El Capitan.
The hidden Data Detector involves airline flight informatioin. This capability is also in iOS 9. However, as far as I know it only works in Apple programs like Mail, Notes, Messages, etc. My wife is flying to San Jose, CA as I write this article. Here is her flight in the Notes application in El Capitan:
She is flying from Denver, but her flight originated from Orlando, Florida. As you can see it shows the airport designations, whether it is on time and a few other things. Pretty cool in my opinion. If you double-click on the map it enlarges like so:
You can see the airline, state names and a few cities. I really like this feature. Yes, they have apps for iOS that do this and more, but for the average Joe it is a nice feature.
Here is the same feature in the Messages app in El Capitan:
Messages hilites the flight information. All you have to do is click on it. It works great let me tell you.
I guess this is not a big deal really, but just a nice little added feature in El Capitan. It seems to work quite well.