orthography - What is the standard rule for using or not using hyphen and diaeresis on the words like reelect , reexamine, and cooperate?

I found that diaeresis is used on the word, reelection in the following sentence of the article titled “Rational Irrationality” in the New Yorker magazine (April 27).

“This morning’s news that economic growth slowed markedly between January and March is an unmitigated bad for Obama and an unmitigated good for Romney. The President’s reëlection chances largely hinge on being able to point to evidence that the economy is finally improving.”

As I don’t think I’ve come across diaeresises being used in the articles of today's journals so often (Correct me if I’m wrong), I checked dictionaries at hand and online.

Cambridge Dictionary online resisters reelection without hyphen nor diaeresis on ‘ee’, same as Merriam Webster online.

Both Oxford Dictionary online and Oxford Advance English Learners’ Dictionary register ‘re-election’ with the former coming with the notation - Spell ‘re-elect’ with a hyphen after the first e. Other words beginning with re- that have a hyphen are re-educate, re-emerge, re-enact, re-enter.

New Yorker used diaeresis on ‘reelection’ as shown above, and their separate article titled “The Curse of the Diaeresis’ (April 2) stated:

“The special tool we use here at The New Yorker for punching out the two dots that we then center carefully over the second vowel in such words as “naïve” and “Laocoön” will be getting a workout this year, as the Democrats coöperate to reëlect the President.”

I find no consistency of the use and non-use of hyphen and diaeresis among Cambridge Dictionary, Oxford Dictionaries and New Yorker magazine.

What is the standard rule or custom of using, not using a hyphen and a diaeresis on the words including ‘ee’ ‘oo’ letters?

Answer

This is hardly some sort of unique New Yorker idiosynchrasy. Rather, it’s merely an older tradition.

Writing Zoë, Noël, reëlect, coöperate, zoölogical, mosaïc, aïoli, cacoëpistic, hyperoödon, haliæëtos, naïve, Moët, naïveté, Thaïs, monoïdeism, panzoöty, Laocoön, langue d’oïl, Boötes, faröelite, caïque, &c is actually an older orthographic style.

This style fell into disuse as people subjected to the infinite tyranny of typewriters (and their ASCII derivatives) bereft of proper diacritics got out of the habit of using things they didn’t know how to type. I rather hate seeing *Zoe written by people who are too lazy to write Zoë properly.

On the other hand, English has never used a diaeresis in words like coalesce, where one might expect *coälesce to differentiate from something related to coal. Similarly, we’ve never used *reäct for react. There is also the tendency to drop hyphens and diacritics from assimilated words. Notice it’s just zoology in modern writing, not the original zoölogy, and you almost always see dichroic and dichroous instead of dichroïc and dichroöus.

I’d sometimes rather see a diaeresis than a hyphen myself if it comes to that. I actually prefer writing coöccurrence, coössify, demosaïcking, reënact, reïnvent (not a rein-vent, whatever that might be), reëxamine, intraätomic, pal(a)eoöceanography, proöxidant, &c to make it clear what’s afoot, where others might use a hyphen or nothing at all. I’m trying to be considerate for the reader, and consistent.

And yes, coopering is a real word, one with three syllables, though, not four. Hence the preference of writing coöperate to show that it has four syllables instead of just three, and is unrelated to coopers.

J.R.R. Tolkien, a very careful writer of English from a slightly earlier era than our own, uses the diaeresis a fair bit in his writings. Consider the raven Röac from The Hobbit; its name is meant to be bisyllabic onomatopoeia for its croaking cry (^{_{or is that croäking?}} :). Or namarië, Eärendel, or Manwë; written using Tolkien’s own phonetic tengwar script, these need no markings to indicate those vowels should be pronounced, but as an aid to English-speaking readers using the Latin script and used to “silent” letters, it helps to mark these explicitly.

By the way, the word diaeresis is so spelled in the Unicode Standard. You will find older books that spell it diæresis, which uses yet another non-typewriter letter. And it is not uncommon to find it spelled dieresis in American writing.