The Affidavit of Civil Status, is an affidavit sworn to by the applicant regarding his/her marital status. This is only available to Cameroonian citizens.
You can come in person without an appointment to the Cameroonian Embassy in The Hague and bring: A fully filled out and signed Affidavit of Civil Status form, from the Embassy Website. You and your two witnesses (who must be Cameroonians) shall be required to sign the form.
You also have to present your valid Cameroon passport and your Birth Certificate. Note that a copy of identification documents of witnesses must be included.