When to use rel=“tag”

Question

I've been looking at the 'Microformat' rel="tag", but am a little confused as to its propper use.

From the spec:

By adding rel="tag" to a hyperlink, a page indicates that the destination of that hyperlink is an author-designated "tag" (or keyword/subject) for the current page.

What do they mean by the 'destination of the hyperlink' is a 'tag'?

In what situations might it be used?

Answer 1

It means the page that link points to will contain a list of links to other pages that are tagged by the anchor text of that link. For example, if a link looked like this:

<a href="/tags/seo" rel="tag">SEO</a>

The microformat tells the search engine, and any other user-agent, that the URL /tags/seo contains links to documents (i.e. pages, etc) that are also tagged seo, and thus related to SEO.

If you have a tag cloud, or put tags on your content pages, you would use this microformat.