Q. Hello. I am alphabetizing something according to the word-by-word system and am curious about whether conjunctions are taken into account. Or are they disregarded as they would be at the beginning of an entry? For example, would the correct alphabetical order be (1) animal experiments, (2) animal and human bond (conjunction ignored), or (1) animal and human bond, (2) animal experiments (conjunction considered)? Thanks for your assistance.

A. In Chicago style, any word occurring in the middle of an entry, including a conjunction, counts in alphabetization (whether word by word or letter by letter), so your second ordering is correct (the a in “and” precedes the e in “experiments”). A conjunction would also count at the beginning of an entry, with one notable exception: index subentries. For example, here’s what an entry for “hyphenation” might look like in a book index:

hyphenation: of compound modifiers, 147; and line breaks, 108; in Microsoft Word, 148

Not only is “and” ignored in the second subentry, but so are “of” and “in” in the first and third subentries; like conjunctions, prepositions are ignored at the beginning of index subentries, as are articles (see CMOS 16.68). But at the beginning of main index entries—and, by extension, any ordinary list—only articles (a, an, and the) are ignored. To make it easier for readers to find things, entries with articles are inverted:

“And I Love Her” (Beatles)
“Day in the Life, A” (Beatles)
Invisible Man (Ellison)
Invisible Man, The (Wells)
On the Origin of Species (Darwin)
Origin: A Genetic History of the Americas (Raff)

Note that the “And” in the first item counts; if it didn’t, “And I Love Her” would be listed second. Note also that if you were to disregard “On the,” Darwin would follow Raff. See also CMOS 16.56 and 16.144.