Demat Debit and Pledge Instruction authorizes broker access to client demat for settlement and pledging, subject to client consent. SEBI prescribes a Demat Debit and Pledge Instruction (DDPI), executable only with explicit client consent and e-signature, to authorize brokers/DPs to transfer securities for exchange settlement obligations and to pledge/re-pledge securities for margin purposes; transfers under DDPI must be matched with client-wise net delivery obligations, credited only to the client's trading member pool account, registered in the client's demat account, and revocable by the client, while brokers/DPs may not compel execution of DDPI or deny services for refusal.