The **`<u>`** [HTML](https://developer.mozilla.org/en-US/docs/Web/HTML) element represents a span of inline text which should be rendered in a way that indicates that it has a non-textual annotation. This is rendered by default as a simple solid underline, but may be altered using CSS.

> **Warning:** This element used to be called the "Underline" element in older versions of HTML, and is still sometimes misused in this way. To underline text, you should instead apply a style that includes the CSS text-decoration property set to `underline`.

See the [Usage notes](#usage_notes) section for further details on when it's appropriate to use `<u>` and when it isn't.