One can find different kinds of content using Administer->Content but it doesn't seem to be possible to find "not categorized nodes" or nodes which are eg. missing in a category.

When there are more than one person adding content (or maybe it is even enough with one person ;) nodes sometimes don't get properly categorized. Depending on how the website is built this can be a rather big problem.

I have one "main" category where it is compulsory to choose one of the terms but not in the 2 subcategories.

How do I find nodes which are not marked with any of the terms in either of the two subcategories?

(I checked the php snippets but cannot seem to find anything appropriate)