I recently installed the Operator extension for Firefox. Operator is an interesting little extension which attempts to expose microformats embedded in web pages through a toolbar in the browser.

While browsing this site with Operator installed I noticed a problem with the tags that are typically attached to each post to organize the site into categories. Drupal attempts to conform to the rel-tag microformat by attaching a rel="tag" attribute to each tag link (Look at the section titled Tags: at the top of this post.) The problem is that drupal uses numbers for each category (aka "Taxonomy Term.") and numbers don't make very readable tags. As several others have already pointed out, this could be considered a deficiency in the microformat. The rel-tag specification doesn't provide any alternate way to specify a text-version of the tag, other than the last segment of the url. In the case of drupal, the last segment of a taxonomy url is the taxonomy term id, which is a number.