Guide to what Cortana keeps local vs sends to cloud?

[RuleOfSines]

I was wondering if there is any documentation that describes what Cortana goes through, and how much of that goes into the cloud.

Does it send email content to the cloud, or is it just getting rules and patterns from the cloud while all the data stays local?

 

[anon(8657436)]

As Microsoft advertise, all stays local. But I have yet to see a documentation but it does send interests to Bing as you can see it in your Bing settings on your browser.