To indicate a break in the flow of a sentence—or an interruption—use an em dash, also known as a long dash. Don't put a space before or after it.
You can type the em dash character in various ways, depending on your platform:
- Press Option+Shift+hyphen.
- Linux desktop environment
- Enable the Compose key. (Instructions for doing that vary depending on your flavor of Linux; for examples, see Linux Keyboard Shortcuts For Text Symbols.) After the Compose key is enabled, you can create an em dash by typing the Compose key followed by three hyphens.
- Alternatively, press Control+Shift+u, then let go of those keys, then type 2014, then press Return.
- Note: These Linux options don't work if you're signed in to the Linux command line from a remote system using ssh or the like; you have to be in a Linux desktop environment.
- Turn num lock on, then hold down the left Alt key and type 0151 on the numeric keypad.
Don't use an en dash (the shorter dash) or a hyphen in place of an em dash. The use of " – " (an en dash with spaces around it) in place of an em dash is gradually becoming more common, but it's still not very widespread in the US in professional publishing; so far (as of early 2016), it's mostly used in Canada and a couple of other places. For now, just use the em dash.
Colons instead of dashes in lists
Another common but nonstandard construction is to use a hyphen surrounded by
spaces to separate an item and its description. Instead, use an HTML
description list (
in some cases, a colon or period.
Not recommended: Example - This is an example.
Better: Example: This is an example.
Recommended for a series of items:
<dl> <dt>Example</dt> <dd>This is an example.</dd> <dt>Another example</dt> <dd>This is another example.</dd> </dl>
Not recommended: Appendix A - My First Appendix
Recommended: Appendix A: My First Appendix