The voluntary nature of classification creates a number of possibilities for a yacht owner. He can pick and choose from the several classification societies that cater to yachts. For instance, an American owner having a fast yacht built in Holland could choose to have it classed by the Norwegian society, DNV (Det Norske Veritas). This is where those detail differences come in, as some designers consider the DNV construction rules for high-speed vessels to be more realistic than those drafted by some other societies. Such shopping for classification is commonplace, and that's why you'll find surveyors for each society in each shipbuilding nation. In an Italian yard, for instance, you might find an ABS surveyor working on one vessel and a Lloyd's inspector working on another, alongside the first. In some cases, where the surveyors are independent, or "non-exclusive" in society parlance, you might find him wearing a DNV jumpsuit one day and ABS coveralls the next.