How to see  data in iOS logs? Looking at iOS 11 logs using Console.app in High Sierra, I see that many important bits of information are masked like this:

nsurlsessiond   Triggering periodic update to powerlog for client &lt;private&gt;
dasd    Trigger: &lt;private&gt; is now [&lt;private&gt;]
Yelp Reservations Map Extension [19 &lt;private&gt; &lt;private&gt;] start


which makes it hard to see what's really happening.  This happens on macOS too, and it can be changed with this command sudo log config --mode 'private_data:on', as described here.  How can I enable logging private data on iOS?
There is no single setting that you can change for iOS logging as there is for macOS.

If you are running a beta version of iOS, the private log information seems to be collected, so that is one option.

The other option is to see if there is a profile on this page that covers the logging you need.

Once you install the relevant profile you will see the previously &lt;private&gt; information appearing in the iOS console log.  

In my case I was able to use the "Baseband" profile to enable caller id logging while working on a CallKit extension. 

To disable the private logging you simply remove the profile from general settings on the device.