You'll be glad to know that Italian rice WAS divided into only 4 categories. Starting with the most humble sort, we'll work our way up to the nobility.

Rice COMUNE

small, high absorption of cooking liquid

medium length grains, used in soups

tapered grains, relatively transparent, stand up well against cooking

large, long, tapered and glassy grains; best for risotto

It's a well-known fact that we Italians can't stand things easy, yet are often incapable of dealing with the complex. The national character thus results in reams of paperwork and continual squabbles over such things as whether a particular rice is 'fino' or 'superfino'.
To ease the tension a bit, as of 1992, rice growers are no longer required by law to indicate the category of their rice on the package, although many still do.
The 1992 law requires only that the varietal name of the rice be clearly visible. What this means in real terms is that originally, shoppers only had to keep the four categories described above in mind when buying rice for specific dishes.

Now, they can have fun with 10 different varietal names to sort out before making a purchase.

From the ordinary to the sublime:

BALILLA

a common variety, quite sticky, which tends to dissolve a bit when cooked.
Ideal for soups and desserts.

a common rice, with short, round grains and a pearly appearance.Highly absorbent, it is used for dishes with long cooking times: desserts, stuffed vegetables, rice croquettes, rice balls, timballi and soups.

a semi-fine rice, sticky, best choice for timballi, formed rice dishes, soups.

a semi-fine rice. Despite its small, round grains, it is a prestigious rice which absorbs seasoning quite well.It can be used for timballi and soups as well as for creamy risottos.

fine rice; firm, highly absorbent grains. Used for timaballi, salads and pilaffs.

a compact golden-grain fine rice. This variety is the best adapted to parboiled use; optimal for stuffed vegetables, pilaffs and salads.

riso superfino, golden-grain, glassy, used in timballi, salads and risottos.

a very starchy riso superfino.The grains are firm when cooked and well-suited to risottos and baked dishes.

riso superfino, large grains, rich in starch, ideal for puddings and creamy risottos.

the most highly regarded of the superfini Made in Italy rice varieties. Its grains are rich in a particular starch which render it firm yet very absorbent. Ensures creamy, al dente risottos and baked dishes.