The Naming and Labeling of Italian Wine
Italian wine is named after the region of production and also, for some varieties, the type of grape used. Thus, Chianti comes from the Chianti region of Tuscany and is made from a range of grape types whereas Montepulciano d'Abruzzo hails from Abruzzu and is made from the Montepulciano grape variety.
You will see bottles labled DOC, DOCG or VDT. These stand for Denominazione di Origine Controllata, Denominazione di Origine Controllata e Garantita and Vino da Tavola.
DOC means that there are controls on where the wine is gown and the grape types and production process employed. In addition to this, DOCG means that the quality of the wine is also guaranteed. That guarantee is pretty worthless. I have poured some Chianti down the drain as unfit for cooking despite the presence of the DOCG mark.
VDT is the lowest awarded grade but that does not mean that it is always poor wine. It just means that the ossified classification structure thought little of this wine when the namings were ratified.
It is not as good a guide to quality as the French system and even that is far from perfect.