 Shari'a apostasy penalties within the legal code limit Christian missionary activities in the north, and the government customarily delayed the issuance of visas to foreigners with affiliations to international faith-based organizations for long periods.The GoSS does not restrict the presence of foreign missionaries, and does not require them to register.Under the state-mandated curriculum, all schools in the north are required to teach Islamic-education classes from preschool through university.