Sidney in Boston, Massachusetts, is curious about the diaeresis, that pair of dots that occasionally appear over a vowel in words such as naïve and coöperate. In ancient Greek diairesis, meaning “division,” applied to those dots in ancient Greek manuscripts, which helped separate syllables in writing that originally didn’t include spaces between words. This mark is also called a trema, from the Greek word for “perforation.” Early in the 20th century, editors at The New Yorker, decided this bit of punctuation would be helpful in words such as reëlect, where two vowels next to each other might suggest a confusing mispronunciation. However, the diaeresis is largely regarded as superfluous by the style guides used by other publications. In her delightful memoir, Between You & Me: Confessions of a Comma Queen (Bookshop|Amazon) a former copy editor at The New Yorker, notes that for many years an editor there stubbornly maintained the need for diaereses, but ultimately told a colleague he planned to discontinue their use. However, he died before sending out that memo, and The New Yorker still uses them today — despite the many complaints from its readers. A diaeresis differs from an umlaut, a diacritical mark that looks exactly the same, that in German indicates a vowel’s pronunciation to differentiate two words from each other. This is part of a complete episode.