In Chapter 3, I covered the use of rel-tag for defining links that indicate what a web page—or part of the web page—is about. I also mentioned this is commonly used for tagging articles and blog posts, providing links to keywords, or tags, that tell what the content is about.
This concept of tagging can be extended beyond links, to keywords for an article or a blog post. Tagging can also be used in bookmarking—that is, how users save and share links to web pages and sites.
Modern browsers support bookmarks. In Mozilla Firefox, Apple Safari (Figure 5.1), Opera, and Google Chrome, users can save links to favorite URLs via the Bookmarks menu, and they can tag these links with keywords.