What do readers of The New Yorker complain about most when they write letters to the editor? Those two dots above vowels in words like cooperate and reelect. The diaeresis, as those marks are known, has remained in use at the magazine ever since the copy editor who planned on nixing it died in 1978, and the whole saga is chronicled in fellow New Yorker copy editor Mary Norris’s new memoir, Between You & Me: Confessions of a Comma Queen. This is part of a complete episode.