Preliminary placement memorandum requirement ensures merchant bankers submit disclosures and due diligence before listing private municipal debt securities. Issuers must file a Preliminary Placement Memorandum for listed private placements through a registered merchant banker, who must submit prescribed disclosures and a due diligence certificate. The regulator may issue observations within a defined period after receipt or after satisfactory replies or external approvals; merchant bankers must incorporate comments into the placement memorandum and provide additional due diligence certificates, and debenture trustees must furnish their due diligence certificate before the private placement opens.