Q. CMOS mentions that titles are commonly lowercase (president of the United States) but that there is an exception with the title of Speaker. There is debate in my office over the titles of archivist of the United States, Smithsonian secretary, and librarian of Congress. If they do not precede a name, do they remain lowercase?
A. Yes, lowercase the titles. After all, how fair would it be to lowercase the president and uppercase the librarian? The Speaker gets special treatment, though, probably because in an institution like the House, where everyone wants to talk and all the talk is recorded for posterity, it has to be clear whether the reference is to the presiding officer (the Speaker) or the person currently blabbing away (the speaker).