A bidder may initially post cash under the ComEd Master Agreement and later change to another type of security to satisfy the performance assurance requirements under the agreement. In the case of a Guaranty, ComEd suggests that you provide draft documents for review to ensure the acceptability of the Guaranty. Once the signed Guaranty in an acceptable form has been received by ComEd, ComEd will initiate the return of the posted cash using the information provided on the coversheet of the ComEd Master Agreement.