Prefixes are particularly common in
Dutch surnames.
Mostly they are
prepositions that create references to towns or geographical features.
Here, 'van' is the most common: e.g.
- Van der Graaff, Van de Graaf, or any other way to spell it, literally means 'from the ditch', but more probably indicates 'from the town of Grave';
- Van den Bos, Vandenbossche, etc. literally means 'from the bush' or 'from the woods', but more probably indicates that the bearer('s family) originated from Den Bosch';
- Van Beek, Verbeek, etc. literally means 'from the creek', but more probably indicates 'from the town of Beek' (of which there are several in the Netherlands) or from a town whose name is locally abbreviated to 'Beek', such as Hilvarenbeek, Vierlingsbeek, or Spaubeek.
Many names unambiguously refer to a town: Van Meurs, Van Arnhem, Van Gulik, Van Keulen.
This kind of name is particularly common on the south of the Netherlands, Belgium (Flanders), and was once used in adjacent parts of Germany. In Germany, however, this type of name became associated with nobility: any surname with 'von' (Von Lippe zu Biesterfeld) implied a title, so the prefix was dropped from family names in Germany (producing surnames such as 'Meurs' and 'Keulen'), and the whole type of name disappeared.
There are many other prefixes in Dutch surnames: In 't Veld (in the field), 't Hart (the heart), De Bakker (the baker), Vennegoor of Hesselink ('Vennegoor' or 'Hesselink').
In the Netherlands, the spelling of prefixes in surnames varies with the name, but capitalization and interpunction doesn't, and when sorting names, prefixes are not considered. For example, Van der Beek and Van de Beek are two distinct names, but Vanderbeek is not used, and both names are sorted under the B, before Beekmans.
In Belgium, on the other hand, capitalization and interpunction are considered to be part of the surname, and sorting considers prefixes; in Belgium, Vander Beek, Vanderbeek and Van der Beek are three different surnames, all sorted under V.
Fortunately, this isn't the node to discuss prefixes in place names (ranging from 's-Hertogenbosch to Sint-Job-in't-Goor).
Some software companies specialize in identifying and sorting address data; it is their business to sort this mess out for others.