Hi Ipigott,
 Thank you for your mail. After reading it, I have looked into the subject a bit, and can see that the Wikicode for adding categories is straight forward - my first step to adding relevant categories. Now I need to find good ways to generate them. Here I have got as far as to the idea of copying category-lines from similar-subject articles. But I am still in doubt about the best other ways, such as by means of some existing lists, search functions for this in Wikipedia, that might exist - or other methods? So if you have got tips, they would be much appreciated. Kind regards.  Old Dane