[topicmapmail] tagging vs topics

[PeterV]

Hi all,
a simple question that I'm sure has been considered by you all before, but 
here it goes: topicmaps are great for assigning topics to articles, but 
what if you also want to *tag* certain parts of an article, ie. "The unrest 
in <country id="CO">Colombia</a> has ...".

Surely tagging is very useful as well. How do you combine tagging with 
topicmaps? What standards do you use for tagging?

Thanks for any thoughts or links to explanations on this,
PeterV
http://easytopicmaps.com