Over the centuries, Italians have instituted many laws to control the origin and protect the names of wines. Even the ancient Romans had defined production areas for dozens of wines. In 1716, the Grand Duchy of Tuscany delimited the zones for important wines, setting a precedent for modern legislation.
Yet only since the mid-1960s have controls been applied nationwide, under what is known as Denominazione di Origine Controllata or simply D.O.C. There are now nearly 300 D.O.C. appellations, all delimited geographically. Wines from 33 zones have been further distinguished as D.O.C.G., the "G" standing for "Garantita" or guaranteed authenticity of wines of "particular quality". D.O.C.G. has expanded from the original five (Barbaresco, Barolo, Brunello di Montalcino, Vino Nobile di Montepulciano and Chianti) to cover many zones around the country where wines must meet strict quality standards imposed and controlled by commissions of experts.
Within the D.O.C. and D.O.C.G. zones, well over 1,000 types of wine are produced. They may be defined by color or type (still, bubbly, or sparkling; dry, semi-sweet, or sweet; natural or fortified), or they may be referred to by grape variety. Wines may also be categorized by age (young as Novello or aged as Vecchio, Stravecchio or Riserva) or by a special sub-zone as Classico or Superiore. The latter may also apply to a higher degree of alcohol or a longer aging period.

Michele Bernetti of Umani Ronchi
D.O.C. and D.O.C.G. regulations limit the varieties of grapes that can be used in the zone. They also set rules about the vinification and aging as well as standards of color, bouquet, flavor, alcohol content, and acidity. Regulations of each D.O.C. and D.O.C.G. appellation are known as "Disciplinare" and are determined by local producers (often grouped in a consortium) overseen by the national wine committee.
Following the trend toward the use of international varietals that did not fit the D.O.C./D.O.C.G. system, Italy introduced the I.G.T. category in 1992. The new appellations include wines that do not qualify for D.O.C. or D.O.C.G., but which are characteristic of a specific area. The limits in terms of grapes allowed, vinification and aging are less stringent and give the producers more flexibility and freedom.