The issuer's right to call back the issue before the maturity date is referred to as a "call provision". In case of asset-backed securities, the trustee is granted the optional clean-up call provision. There are variants of such provisions.

Percentage of collateral call: In this case, bonds that are outstanding can be called at par value if the value of the outstanding collateral goes below a prespecified percentage of the original collateral's value.

Percentage of bonds clean-up call provision: In this type, bonds are called at par value when the percentage of the amount of outstanding bonds relative to the original amount of bonds issued exceeds a particular level.

Latter of percent or date call: The bonds outstanding are called in either of the two situations: (i) the value of the outstanding collateral reaches a predetermined level before the specified call date or (ii) the call date is reached but the value of the outstanding collateral still remains above the predetermined level.

Auction call: Here, call option will be exercised if, on a particular date, the value of the outstanding collateral is sold in the auction at a price greater than its par value. The excess amount received on the auctioned collateral is retained by the trustee and then subsequently paid to the issuer through the residual.

Insurer call: This call provision permits the issuer to call the bonds when the cumulative loss on the collateral reaches a particular level.