Tussenvoegsel

A tussenvoegsel (pronounced [ˈtɵsə(n)ˌvuxsəl]) in Dutch linguistics is a word that is positioned between a person's first and last name similar to Irish or Scottish surname prefixes, French particules or German von. The most common tussenvoegsels are "van" (as in Vincent van Gogh; see also van (Dutch)) meaning "from" and "de" (as in Greg de Vries), meaning "the". Other Dutch surnames include no tussenvoegsel (as in Mark Rutte and Wim Kok).

The use of tussenvoegsels differs between the Netherlands and Belgium.

In the Netherlands, these tussenvoegsels are not included when sorting alphabetically. For example, in the Dutch telephone directory the surname "De Vries" is listed under "V", not "D". Therefore, in Dutch databases tussenvoegsels are recorded separately. This often simplifies finding a Dutch surname in a Dutch database, because including the tussenvoegsel would result in many surnames being listed under "D" and "V".

According to Dutch language rules in the Netherlands, the tussenvoegsel in a surname is written with a capital letter only when it starts a sentence or is not preceded by a first name or initial. So referring to a Peter whose surname is "de Vries" we write "meneer De Vries" (Mr De Vries), but "Peter de Vries" and "P. de Vries".

In Belgium, surnames are collated with the full surname including tussenvoegsels. "De Smet" comes before "DeSmet" in a telephone book. Although Francophone surnames commonly also have tussenvoegsels, those are frequently contracted into the last name, turning e.g. Le Roc into Leroc or La Roche into LaRoche, thus explaining the collation preference.

In contrast to Dutch orthographic rules, in Belgium tussenvoegsels always keep their original orthography, as in meneer Van Der Velde, meneer P. Van Der Velde or Peter Van Der Velde.

...
Wikipedia