# title
Medication administration  performer  function  codes

# concept[].definition
A person, non-person living subject, organization or device that who actually and principally carries out the action

# concept[].definition
A person who verifies the correctness and appropriateness of the service (plan, order, event, etc.) and hence takes on accountability.

# concept[].definition
A person witnessing the action happening without doing anything. A witness is not necessarily aware, much less approves of anything stated in the service event. Example for a witness is students watching an operation or an advanced directive witness.