Standard phrase for passing control over a plane from one pilot to another, to ensure the other person knows you're handing over it, and to acknowledge the control has been passed. It probably wouldn't be uncommon for remote surgical devices if you need to transfer control over that, too.
Oh, but Patchu forgot the acknowledgment! Alert the CRM nazis! ^_^
It's supposed to have 3 steps: The pilot giving up control will say "You have control." The person taking control says "I have control." THEN the person who no longer has control is to acknowledge this, by saying "You have control." again.
This means there are always 3 steps in a willing transfer of control, and 2 steps in an involuntary transfer of control.
Of course, the third step is often skipped outside of airline flying. For example, with me and my instructor, it was just "Your plane"/"My plane".
