So namespaces are structure which is what I was after. But tags are like the keywords that robots use to index web pages?
I like it. I presume that helps when one uses the search function. Or am I totally missing the point?
Well, it's not really used for the search function itself. Really, it's more of a grouping. Like "Show me all articles tagged with the keyword 'networking'".
But the thing is, you're much better off if you just have easy to use page navigation. IMHO 'tags' are usually just a crappy band-aid for admins who can't figure out how to make a decent navigation system for their sites.
@ inthewoods, afaik most search engines look for keywords inside <meta> tags.
Actually, pretty much all modern search engines completely ignore meta keywords. Too easy to just spam whatever tags you want in there.