The pilot in command is just that, the pilot in command. It is a requirement of the law. As to the duties in the cockpit (Handling or Monitoring), these will be largely depicted by the type (I.E taxiing a boeing) and also the company SOP's.
Simple really.
To think that there are still those that believe that the command difference is all about calling for the checklists and that somehow it's important. Sheesh, this is the 21st century you know..!