Which method is not used by the SEC to clarify its expectations under the Investment Advisers Act of 1940?

The SEC utilizes various methods to communicate its expectations and clarify regulations under the Investment Advisers Act of 1940. Among these, no-action letters, policy statements, and interpretive letters serve distinct purposes. No-action letters provide assurance that the SEC will not take enforcement action if a particular course of action is followed, giving firms guidance on compliance. Policy statements articulate the SEC's stance or broadcasting its priorities, while interpretive letters offer insights into how the SEC interprets certain aspects of the law, which allows advisers to better understand their obligations.

In contrast, technical service bulletins are not a recognized method for clarifying SEC expectations under the Investment Advisers Act. They are typically used in different contexts and do not pertain directly to investment advisor regulations or the SEC's processes for explaining its expectations. Hence, identifying technical service bulletins as the method not used by the SEC emphasizes the specific tools that the SEC employs to provide clarity and guidance in regulatory contexts.