Many Dutch family names have prefixes such as:
van, van de, van der, van ’t, ten, te, etc.

It is common use that capitals are only used at the first prefix when the Christian name or its initials are not used.

In alphabetical listings the prefixes are always ignored, family names are categorized on the noun after the prefixes. A name such as, Van den Heuvel, would be categorized under “H”.

In Belgium a family name as (Dutch spelling:) “Van den Heuvel” will often (but not always, depending on the choice of the family in previous times) appear as: Van Den Heuvel, categorized under “H”, or as Vandenheuvel, and subsequently be categorized under “V”.
In case in Belgium when the prefixes are written seperately, they use: Van Den Heuvel (all capitalized) in most cases.

Furthermore: In most other countries these names are often written as Vandenheuvel or VandenHeuvel.

Throughout the genealogy the Dutch spelling of family names is used. This may sometimes lead to some confusion in case of double names, and for that reason an explication on the ways double names are used internationally has been included here.
Several Dutch families have ‘double’ names, so have many of the Kolff’s: Van Santen Kolff, Kolff van Oosterwijk, Van Breda Kolff, and - rather recent - also Kolff Breymann.

In the Netherlands a double family name is never connected by: “ – ” as they are, for example, in England or Germany. So anyone named: Benthem Reddingius as the family name would never be hyphenated. If she marries a Kolff, her name would be written as: Mrs. Kolff-Benthem Reddingius.
Hyphens are used in Dutch family names, but only for women when they use their husbands name and their maiden name (as the example shows, and which is used very often; more about this at right).

Contrary to general practise in the Anglo-American world Dutch women keep their maiden name, but it gets connected by a “ – ” to the husbands name that preceeds it (unless, nowadays under new legislation, they decide differently: e.g. the female keeps her maiden name as her family name, or, the husband - also legally possible - decides to take the wife’s name).

New legislation in the Netherlands may make things more confusing: in case of same sex marriages couples can choose the name they want to use. The Kolff Family Association follows Dutch legislation (see: Association: Regulations [most recent Regulations date from 2001]) in membership to the Association and inclusion in the Genealogy. This is one of the reasons why, in many cases, the children of female Kolffs now appear in the Genealogy: they are included when the family name Kolff has been choosen for them (according to Dutch law they can opt for change, once, when reaching maturity in order to enable them to decide for themselves).