Tagging and Category

Tagging is the new buzzword on the net, thanks in large part to Flickr and Delicious. There is a push, with podcasting included, on how to automatically tag rss content. Delicious has opened their api and certain sites are adding delicious tags onto each posting.

Within the rss spec, there is an optional element of category that directly allows the entry of keywords. This could easily be transformed into tagging and allow for aggregators to tag content and aggregate keywords.

This seems like a simple and graceful way to add tagging to rss feeds without using an additional service. The possibility for searching, aggregating, and filter are incredible if this optional element begins being used...