Excise exemption for supplies to special economic zone: duty relief subject to export documentation and customs certification. Exemption applies to excisable goods supplied to units in a special economic zone, exempting whole of central excise duty and additional duty, provided removals follow rule 11 procedure, supplies are against an assessed bill of export or a domestic procurement certificate issued by SEZ customs authorities, and proof of export certified by the Deputy or Assistant Commissioner of Customs in the SEZ is submitted to the Central Excise range officer within one month of removal.