For a Norwegian document to be valid abroad, it has to have an Apostille stamp. An Apostille stamp is available from the County Governor (Fylkesmannen). Before a document can receive an Apostille stamp, the translation first needs to be notarised, that is, signed by a Notary Public.
An Apostille stamp does not verify that the content of the document is correct, but it confirms that the signature of the notary public is genuine. This is called legalization.
For more information, please read at www.fylkesmannen.no.