Definition: Perpetual floating-rate notes
External debt - IMF
A debt security whose coupon is refixed periodically on a refix date by reference to an independent interest rate index such as three-month LIBOR. Generally, these instruments are issued by financial institutions, particularly banks, and are perpetual so as to replicate equity and qualify as tier-two capital under the Basel capital adequacy requirements. Investor demand for perpetual floating-rate notes has been weak in recent years.
International Monetary Fund (IMF), "External Debt Statistics: Guide for Compilers and Users; Appendix I. Specific Financial Instruments and Transactions: Classifications", Washington D.C., 2003