The text translates to: "Join us for a lovely march." The poster concept appears to be to turn bigotry on its head.
SOS Rasisme was started in Norway in 1985, with inspiration from SOS Racisme in France. The purpose was and is to create a broad alliance against racism whether it is organised racism/nazism, institutionalised racism or "every day racism."
SOS Rasisme in Norway is a member of the International Federation of SOS Racism.