Specification of debentures under tax provision identifies eligible Flexibonds series and exact instruments for tax treatment. The Central Government designates specific debentures in Industrial Development Bank of India's Flexibonds 14th series for the purposes of the relevant tax provision by identifying named bond types (Regular Income Bond, Retirement Bond, Growing Interest Bond), distinguishing physical and demat holdings, and assigning exact distinctive number ranges and face value where applicable to define the instruments covered.