Archaic Punctuation
Two-Em Dash
My favorite punctuation mark right now is the two-em dash. There is very little information about this mark on the web, and all of it is incorrect, claiming that the two-em dash is only used to indicate letters that have been left out of a word. I am here to set the record straight.

First, recall how the ellipsis is often misused;— and mis-kerned;— nowadays. A typical misuse is to indicate a pause in voiced or unvoiced conversation:

“I am not sure . . . let me think about it.”

This is unequivocally an complete violation of the proper use of an ellipsis. The ellipsis is correctly used to indicate when part of a quoted text has been left out. Using it for this other purpose leaves us wondering “Is he pausing in speech or is there something he said that the author is not revealing for some reason?” We often can't tell.

Some sort of dash should have been used in the above example instead. One possibility is the two-em dash:

“I am not sure —— let me think about it,” he said reluctantly.

If the person’s pause was not quite so long, the standard em-dash would have been sufficient:

“I am not sure — let me think about it,” he said sincerely.

The two-em dash is for long pauses that exceed the length of a standard em-dash pause. It is also used when you are hiding a person's identity by abbreviating their name, such as,— “During our expedition to Kathmandu, we encountered a Mr. Q——, a former barrister of London, tending mountain goats in a remote valley of the Himalayas.”
Reëxamine
I saw this spelling of reexamine in the New Yorker this year. I want to say to the editor, for real, dude? You are spelling reexamine with an umlaut? It's like: Oh. My. Gawd.

Isn't this just an example of pretentiousness gone waaaay too far?

The New Yorker actually mandates this usage in their style guide, along with such wonders as "The New Yorker mandates that authors must coöperate to reëducate our readership." As well as zoölogy, coördination, and so forth. They also point out that the umlaut is no umlaut in this usage but is rather a diaeresis.

The correct punctuation mark to use when breaking up things in this way is the interpunct, or punt volat. It's used in Catalan to distinguish between the standard doble ela 'll' and the ela geminada l·l. This is exactly the same purpose,— to prevent letters from coalescing into a phoneme;— such as these common cases of double letters that could, possibly, be interpreted as a long vowel sound, if read by a space alien who had never read the New Yorker, and was not yet very familiar with English: “Ree-cha-mee-nay, what is that?”

The interpunct reads and flows better, it is not a distraction, people are used to it, and it does not bring the sentence to a screeching halt as it desperately calls attention to itself. Use it well. On the Mac, opt-shift-9 summons the interpunct.

"We, the punctuative literate, ask that the board re·examine its mandate that authors should have to co·operate in re·educating their readership."