Specification of telephone bonds under income tax provision permits issuance of secured multi year redeemable non convertible bonds by MTNL. Central Government specifies issuance of taxable secured redeemable non convertible telephone bonds by Mahanagar Telephone Nigam Ltd as the 10th Series Issue for purposes of the income tax provision, detailing three five year tranches identified by distinctive serial number ranges, aggregate issue amounts, denomination and the secured redeemable non convertible character of the bonds.