I want to have basically a second set of categories, so I can have different industries listed, and clients listed as subcategories of the industries, without interfering or being a part of the regular category list. Can I do this somehow?
I could also do this with tags if you could somehow group tags together?
I think I can explain more clearly as I am after the same thing…
In drupal you can create any number of taxonomies that can be hierarchical, flat etc. I.e. you can create multiple category trees or multiple tag fields and then add the post in to some or all of the various taxonomies.
This is really useful where you may want user-tagging of posts in one, and editorial tagging of posts in another.