The legislative body of a covered county that issues bonds under this subtitle shall determine: the time or times when interest is to be paid on the bonds; the time or times when the bonds are to be executed, issued, and delivered; the form, denomination, and tenor of the bonds; the time or times when the principal of the bonds is to be paid, which may not be more than 40 years after the bonds are issued; and the place or places where the bonds are to be paid. The bonds may be secured by: a pledge of mortgages or notes secured by deeds of trust on any type of interest in real or other property, including the real property or other interests held by stock cooperatives or condominiums and their unit owners; servicing agreements; condemnation proceeds; private, governmental, or other mortgage insurance proceeds; casualty or special hazard insurance proceeds; or any other security that the legislative body of the covered county finds appropriate. The bonds may provide that, at the option of the covered county, the bonds or any one of them may be called for redemption before maturity, at a price and under the terms and conditions that the legislative body of the covered county fixed before issuing the bonds. The following are exempt at all times from taxation of every kind and nature whatsoever by the State or a county: the principal of a bond; the transfer of, interest payable on, or income derived from a bond; and profit made by the sale or transfer of a bond. A bond issued under this subtitle is a negotiable instrument. A covered county may: issue its bonds in coupon form; or provide for registration of the bonds as to principal alone or principal and interest. The bonds shall be signed by a commissioner or other chief executive officer of the covered county. The seal of the covered county shall be affixed to the bond and attested to by the clerk or the officer exercising the functions of a clerk. An officer’s signature or countersignature that appears on bonds or coupons is valid even if the officer leaves office before delivery of the bonds.