PPMN_ — Need more precise definition of Custody

At the moment it's self-referential "Custody indicates that the source element has custody of the target element."
There are nuances and legal aspects to consider.
For example, if someone is working for a company does the company or the employee have "custody" of the Entity they're working on? Legally it's the Company.
If an Entity is lost or stolen does the finder, or thief, have custody? Legally they do not, apparently.