In all cases, both the borrower and all recognised guarantors must be assigned a borrower rating at the outset and on an ongoing basis. A bank must follow all minimum requirements for assigning borrower ratings set out in this section, including the regular monitoring of the guarantor's condition and ability and willingness to honour its obligations. Consistent with the requirements in section CA-5.8.43, a bank must retain all relevant information on the assignment of an exposure to a pool, and the estimation of PD.