There is conflicting documentation that states CLVisit does/does not require the Location updates in background modes. Does it require background modes? Also, if it does, then why? Signficant Location Change does not, and they are extremely similar.
In iOS9, does CLVisit require checking Location updates under Background Modes?
The 'location' key in UIBackgroundModes is NOT required to use CLVisit.
Due to the nature of how CLVisit works in the background, the system will handle the monitoring for you and activate/launch your app to call your delegate methods when needed.
But you still need to ask for 'always' authorization to access location data in the background.
You can find more about it in the WWDC 2014 "What's new in Core Location" session: https://developer.apple.com/videos/wwdc/2014/
Please do file a Radar against the documentation that you think may be wrong or confusing, so the documentation team can re-word as necessary.