from The Trouble With EM ’n EN (and Other Shady Characters):

The em dash (—) is used to indicate a sudden break in thought (“I was thinking about writing a—what time did you say the movie started?”), a parenthetical statement that deserves more attention than parentheses indicate, or instead of a colon or semicolon to link clauses.

that’s from an article about how html handles common typesetting scenarios, which is a genre that traditionally had belonged to print. i’m researching this because i’m about to send a brochure to print, an almost $900 job order, and i’m looking at two paragraphs where it says things like this:

The next step — hiring our client — is up to you, the creature in the purple suit.

i’ve been looking at those two instances and thinking, “that doesn’t seem right.” because a few years ago i worked in the word processing department of a utility company where my entire job was to proofread and properly format legal documents, and the head of the department was very chicago manual of style manual-obsessed, and we would spend hours erasing empty spaces at the ends of paragraphs, and converting soft spaces to hard spaces, etc.

so it appears that my above sentence, “hiring our client” should instead be surrounded by 2 em dashes, no spaces, because it’s a parenthetical thought. if i were creating this using microsoft word, this’d be rather easy, as if you put two hyphens together word automatically converts them to an em dash. (i can’t remember, off the top of my head, what you do if you want an en dash instead; all i can remember is that i always got the two, em and en, confused.) but when i type two hyphens next to each other in indesign, it doesn’t automatically convert. which seems odd, as given indesign is marketed as print/”typesetting” application, shouldn’t this be a default attribute? and i can’t intuitively figure out how to create an em dash. 3 pages of google results didn’t turn up the answer, and then it occurred to me to use indesign’s help menu. it tells me:

You can insert common characters such as em dashes and en dashes, registered trademark symbols, and ellipses.

Using the Type tool, position the insertion point where you want to insert a character.
Choose Type > Insert Special Character, and then select an option from any of the categories in the menu.

when you go into the type menu to try this out, it tells you what the shortcuts for entering em and en dashes are, which is pretty handy.

(click to see the full menu path)

still, though, it’d be nice to see a conversion functionality like microsoft word has. when i used to do word processing, we had all sorts of shortcuts and tricks; oftentimes find & replace and the autocorrect feature would save us lots of time. in indesign’s preferences menu it has an autocorrect tab where, if you enable autocorrect, it’ll automatically change misspelled words to correctly spelled words. it also lets you add custom autocorrects, for instance, let’s say that there’s a very long scientific word, like pneumonoultramicroscopicsilicovolcanoconiosis (one of my favorite words from when i was a kid). instead of typing out that word each time, you can just type “pneumono” and then it’d automatically autocorrect with the entire word. (here’s a web page that goes into indesign’s autocorrect feature in a little more detail.) i tried to add a custom autocorrect in which anytime i entered two hyphens right after each other it’d replace it with an em dash, but it told me the command was using invalid characters. oh well, it was worth a shot.