Opium act (drugs)
You are not allowed to bring narcotics (goods falling under the Opium act - only available in Dutch) across the Dutch border. It is allowed, as an exception, if you have a licence for it. The Minister of Health, Welfare and Sport grants these licences for the Netherlands.
Customs checks at the European external borders if you have a licence.
Goods falling under the Opium act are, for example: