Debenture maturity requirement restricts public debentures eligible for surtax treatment to long term non redeemable instruments. Amendment revises schedule rules to identify public debentures referenced in clause (iv) as qualifying only if, by their terms, they are not redeemable before the expiry of a seven year period from issue, and substitutes corresponding cross references and wording in rule 3 to cover issue of those debentures, borrowings in clause (v) and reductions on account of paid up share capital reduction or redemption of such debentures.