Text that needs to be underlined: links
Since the beginning of the web, links have been underlined. People expect it.
Yes, we have many more visual treatments at our disposal today, including backgrounds and hover states (at least on non-touchscreen devices). Those are all good in addition to underlining, but they don’t mean removing links’ underlining is a good idea.
Maybe you prefer the look of links that aren’t underlined. Your visitors’ expectations, though — when they aren’t met — make their experience of your website more frustrating. That’s not one of your site’s goals.
Text that needs not to be underlined: publication title & things to be emphasized
- Emphasis is better-achieved through the judicious use of italicization or bold-faced type.
- Titles of books, movies, etc., should be italicized (or regular, non-italicized when part of an already-italicized passage).
Underlining text that isn’t part of a link is bad for the same reasons that not underlining links is — it runs counter to your visitors’ basic expectations of how websites work.
Let’s embrace 21st-century publishing instead of the limitations of manual typewriters.