"Vancouver" is just a string of letters that have meaning to humans, in my case when tagging content on my blog, the city of Vancouver. Machines don't know this for sure, however, and for any future machine to come along and do something meaningful with the content on justagwailo.com/tag/vancouver as it pertains to the city of Vancouver, British Columbia, I will need to 'machine tag' the Drupal taxonomy term with a URL identifying it unambiguously as referring to the city. The links below propose an RDFa solution to this, though there is no module to automatically mark up the HTML in RDFa.
<body class="page page-taxonomy page-taxonomy-term page-taxonomy-term-1">Bits in red would be added by the Common Tag module.
Node example (in progress):
<div id="node node-321"> <!-- created by the theme's node.tpl.php -->
[Content about baseball here.]
</div> <!-- /terms -->
</div> <!-- /node -->