Q. With regard to this Q&A, I believe you have misanalyzed the meaning and etymology of the singular word corps.
Q. When referring to “the corps” as in the Army Corps of Engineers or the Peace Corps, what is the proper possessive form? For example, is it “the corps’ decision” or “the corps’s decision?”
A. Use corps’. Please see CMOS 7.19 for the possessive of nouns that are plural in form, singular in meaning.
You give a solution based on CMOS 7.19, but actually CMOS 7.16 applies to singular words ending in silent s (e.g., corps, Illinois, Jacques, rendezvous, chamois). CMOS 7.19 refers to words that are plural in form but singular in meaning. However, words like corps or chamois are not plural in form. The word corps, for example, is singular in both form and meaning. It comes from the French le corps. The s on the end is from the original Latin spelling corpus, which is also singular. The s does not signify plural and never has. (The Latin plural is corpora.) We use the invariable plural form that French does in spelling, but in English the singular is pronounced /kor/ and the plural, which happens to be spelled the same, is pronounced /korz/. Thus, by CMOS 7.16, the possessive forms should arguably be “the corps’s plan” (singular) and “the many corps’ plans” (plural).
Q. In your April Q&A, you answered a question about “woman pilot” vs. “female pilot.” I’m surprised that you didn’t address the unspoken aspect of the question: why mention gender at all? I’m guessing no one says “man pilot” or “male pilot,” just as people don’t say “white doctor,” but they do say “black doctor” as if gender and color are only worth noting if the people don’t belong to the dominant demographics. Does Chicago have any thoughts about that?
Q. Hi, CMOS staff. My question itself concerns two Q&A entries. In the first one, it looks as though a department name, even when part of a long corporate title, gets capped: “Mary Smith, director of Human Resources.” In the second one, though, it appears that if an otherwise would-be-capped department is a part of the title, it too gets lowercased: “Jordan Smith is assistant secretary of bureaucracy and obfuscation.” I’m editing a book that is constantly shifting its capitalization patterns for these departments (such as “chair of the Department of Physiology and Neuroscience” and “the head of the emergency department”), and I’m having a hard time determining which way to jump, because the advice in these Q&A entries seems to be contradictory. Could anyone shed some light on this for me?