As part of these protections, the custody rules require an investment firm licensee to take appropriate steps to protect safe custody financial instruments for which it is responsible. These rules are designed primarily to restrict the commingling of client and investment firm licensee assets and minimise the risk of the client's safe custody financial instruments being used by the firm without the client's agreement or contrary to the client's wishes, or being treated as the investment firm licensee's assets in the event of insolvency.