Dematerialisation requirement: securities may shift from trade-for-trade to rolling settlement when non-promoter holdings are dematerialised. Shifting securities from Trade-for-Trade Settlement to Rolling Settlement is allowed once a company connected to both depositories demonstrates that at least 50% of other-than-promoter holdings are dematerialised via a certificate from its RTA or, if no RTA exists, from a practicing Company Secretary or Chartered Accountant; exchanges must also confirm absence of other grounds for continuation of TFTS and report the action in their development reports to the regulator.