"Comparables" is a real estate term referring to properties which are similar to a particular property and are use to compare and establish a value for that property. Appraisals of properties employ the use of comparables to determine fair market value.
"Credit enhancement" is credit support purchased by an issuer to raise the credit rating on a debt issue. The most common types of credit enhancements include municipal bond insurance, letters of credit, corporate guarantees, lines of credit, reserve funds, or over-collateralization. The credit enhancement is used to obtain a better credit rating on the debt issuance or to lower required interest payments.