Excerpts of the President's News Conference
It wouldn't be possible to make any change in the rules that govern the conduct of a conference between the newspaper association and the President. Every one of you men who come in here to the conference know what those rules are and the need to observe them carefully. I speak of the question that has been propounded here relative to quotation. If anybody has any doubt about it, let him consult with the Secretary of the White House Press Association, who will give him all the information he desires.
Source: "The Talkative President: The Off-the-Record Press Conferences of Calvin Coolidge". eds. Howard H. Quint & Robert H. Ferrell. The University Massachusetts Press. 1964.
Calvin Coolidge, Excerpts of the President's News Conference Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/349105