Do you mean POWER OF ATTORNEY?
In the United States, Attorney-at-law means a lawyer. The distinction is made because people can have "power of attorney" or "letter of attorney", which is referred to as Attorney-in-fact.
Attorney In Fact. Very similar to, if not same as, Power of Attorney.
Do not oppose means to not to talk when he is stating his arguments unless the attorney is harassing the client of another attorney. Thou that is not a good for close.
Do you mean like "Bankruptcy Attorney"? Well it is a title of sorts. So yes. I am Max Rosenberg, the Bankruptcy Attorney.
Attorney
There is no such thing as Secretary of Attorney. Do you perhaps mean Attorney General? Or do you mean what does an attorney's secretary do?
Any person having the capacity to contract is qualified to act as an attorney-in-fact.
District Attorney
An attorney is an agent, someone who acts on your behalf. A Power of Attorney is a document under seal which appoints someone to act on your behalf. In the United States, lawyers are called attorneys, presumably because they are frequently asked to act on behalf of others.
AG can mean attorney general.
Professional corporation.