As per apnaqanoon,Regards regional languages like Punjabi, Sindhi, Balochi, Pashto, Brahvi, Hindko and Siraiki, Clause (3) of Article 251 empowers the Provincial Assembly by law/qanoon to prescribe measures for teaching, promotion and use of a provincial language in addition to the national language.
What Is 251 Article Of Pakistan Constitution As Per QANOON
