To give the delivery instruction to DP you have to fill one form called Delivery Instruction Slip (DIS). DIS may be compared to cheque book of a bank account. The following precautions are to be taken in respect of DIS
Ensure and insist with DP to issue DIS book;
Ensure that DIS numbers are pre-printed and DP takes acknowledgment for the DIS booklet issued to investor;
Ensure that your account number [client id] is pre-stamped;
If the account is a joint account, all the joint holders have to sign the instruction slips. Instruction cannot be executed if all joint holders have not signed;
Do not use loose slips;
Do not leave signed blank DIS with anyone viz., broker/sub-broker; and Keep the DIS book under lock and key when not in use.