Tags and Catagories

It is debatable whether tags are better or categories. I prefer tags but I have a question, I’m using a tag add-on that relies on the wp_tag syntax so if I wanted to setup my tags so I have categories within the tags would I have to use Taxonomies as such;

<tagname>,<tagname>,<tagname><TAG CATEGORY(larger font)>,<tagname>,<tagname>,<TAG CATEGORY>,<tagname>,<tagname>??

Most tag clouds give larger fonts to more popular tags used, so if you tag each post with the category then yes it would be bigger. You probably could tweak settings to give the tag category a bigger size.

My tag cloud doesn’t work like that, arrrgh I want one that works like that.