The term "perpetual preferred stock" means a preferred stock that does not have a stated maturity date or that cannot be redeemed at the option of the holder. It includes those issues of preferred stock that automatically convert into common stock at a stated date. It excludes those issues, the rate on which increases, or can increase, in such a manner that would effectively require the issuer to redeem the issue; provided, however, that banks may issue floating rate preferred stock issues where the rate is constant in relation to some base rate.
N.M. Admin. Code § 12.16.21.7