MRP based duty on medicaments: abatement of retail sale price allowed for specified medicaments under section 4A. The notification makes medicaments under Chapter/Heading Nos. 3003 or 3004 subject to the provision allowing duty computation by reference to retail sale price and permits an abatement (specified in the Table) of retail sale price for two categories: patent or proprietary medicaments and other medicaments, both excluding those exclusively used in Ayurvedic, Unani, Siddha, Homoeopathic or Bio chemic systems. 'Retail sale price' is defined by reference to the Drugs (Prices Control) Order and 'patent or proprietary medicaments' is defined by reference to pharmacopoeial nomenclature and branding.