- Capacity refers to a specific function or status, not necessarily the usual or customary one the judge spoke to him in the capacity of a friend
- Duty is applied to a task necessary in or appropriate to one's occupation, rank, status, etc. and carries a strong connotation of obligation the duties of a vicar
- Office , in this connection, refers to the function of a person, as determined by his position, profession, or employment the office of a priest
- Function is the broad, general term for the natural, required, or expected activity of a person or thing the function of the liver, of education, etc.