For Your Typographic
Now that you’ve nailed the difference between hyphens, en-dashes and em-dashes, surely there can’t be any more little horizontal lines to learn about? In fact, you can add one more term to the mix: the discretionary hyphen, an application-based hyphen with a brain.
In simple terms, discretionary hyphens know how to become invisible unless needed. A discretionary hyphen is manually inserted where you, the user, want a word to break if and when that word appears at the end of a line. If the text reflows and the need for hyphenation is eliminated, the hyphen disappears.
Use a discretionary hyphen (sometimes called a ‘soft’ hyphen) rather than a ‘hard’ hyphen whenever you want to overrule or tweak the automatic hyphenation generated by your application. This way you’ll prevent those nasty hyphenated words that can unexpectedly appear in the middle of a line when text is reflowed (we’ve all seen this atrocious occurrence!).
The discretionary hyphen also has a lesser-known but very useful feature: if you place it in front of a word (or a string of characters acting as a word, such as an email address), that word will never be hyphenated (and the hyphen, of course, remains invisible). This is a good way to prevent email addresses, URLs, proper nouns and words in headlines from being split in two by your application’s automatic hyphenation settings.