Tax-free Railway Bonds permitted with tranche-based interest, subject to mandatory registration of each bondholder. Authorisation under section 10(15)(iv)(h) permits issuance of tax-free secured, redeemable, non-convertible Railway Bonds in tranches with interest varying by size and tenor, subject to aggregate issuance limits; the interest exemption is admissible only if each holder registers their name and holding with the issuer.