Concessional duty eligibility confirmed for SBOC used via intermediate TPR in manufacture of soles, subject to end use bond. Concessional duty under Notification No. 20/99-Cus. applies to SBOC listed in List 3A where SBOC is converted into TPR compound used to produce TPR soles for use by footwear manufacturers in the leather industry; insofar as List 3A imposes no additional condition analogous to List 3B, the concessional rate is available, subject to safeguards such as end use bonds and finalisation of pending provisional assessments consistent with Board instructions.