Documents from certain countries must be legalised or have an apostille. More information can be found on the website for the legalisation of documents by the Dutch government.
Some foreign documents must be translated into Dutch (or English for study programmes taught in English) by a certified translator. The municipality will verify the authenticity of the identity documents.
If foreign documents have been issued by the relevant authority in French, German or English, these will often be accepted. Documents issued in other languages need to be translated by an official translator.