Jorge Luis Borges is famous for the classification of animals supposedly to be found in the Celestial Emporium of Benevolent Knowledge:

1. those that belong to the Emperor,
2. embalmed ones,
3. those that are trained,
4. suckling pigs,
5. mermaids,
6. fabulous ones,
7. stray dogs,
8. those included in the present classification,
9. those that tremble as if they were mad,
10. innumerable ones,
11. those drawn with a very fine camelhair brush,
12. others,
13. those that have just broken a flower vase,
14. those that from a long way off look like flies.

For no readily accountable reason, that came to mind this afternoon looking at a list of customer needs groups.