printing.]

I am also not sure how far back your 'always' (above) stretches. I think
most of the classification schemes we use now in science started in the 17th
Century and business in the 19th - though I would be interested in more
information on this topic.

The problem we face is that when we try and use the schema produced by
'practical classification' in computer systems of any reasonable size we
start getting problems of inaccuracy - or lack of fit. For example, I am at
the moment involved in working