Genealogy – The Youngest Kolffs (from 2011)
| Name | Born where and when | In Genealogy |
| Sven Frederik Sebastiaan Kolff | Amsterdam, Netherlands, 12 September 2013 | CBCD XIXt |
| Pim Erik Kolff | Amsterdam, Netherlands, 20 August 2012 | CBB XIXi |
| Jet Margaretha Irene Kolff | Rotterdam, Netherlands, 2 August 2012 | CBCF XVIIIee3 |
| Viggo Laurens Michael Kolff | Amsterdam, Netherlands, 14 november 2011 | CBCD XIXt |
| Victor Jacob Kolff | Geneva, Switzerland, 9 May 2011 | CBCB XIXr2 |
| Sweder Frans Coenraad Kolff | Haarlem, Netherlands, 25 February 2011 | CBCC XVIIIv2 |
| Isa Johanna Kolff | Hoofddorp, Netherlands, 11 December 2010 | CBCF XVIIIx2 |
More new born children (not named Kolff) in Members: Notices (only accessible with a password).
The Youngest Kolffs are shown here at least up to the end of the year following their birth.