In HTML, the <u> tag is used to underline text on a Web page, often for emphasis. There has been much debate about whether underlining important keywords can increase a page’s ranking in search engines. Most SEO professionals agree that if there is any value to underlining text, it is negligible. It can also confuse visitors, who may interpret underlined text as a link. The tag has been deprecated by the World Wide Web Consortium, meaning that it has been replaced by other, more useful tags.