Looks like a keystone to me
"The Senior Executive Service (SES) lead America’s workforce. As the keystone of the Civil Service Reform Act of 1978, the SES was established to “...ensure that the executive management of the Government of the United States is responsive to the needs, policies, and goals of the Nation and otherwise is of the highest quality.” These leaders possess well-honed executive skills and share a broad perspective on government and a public service commitment that is grounded in the Constitution.
"Members of the SES serve in the key positions just below the top Presidential appointees. SES members are the major link between these appointees and the rest of the Federal workforce. They operate and oversee nearly every government activity in approximately 75 Federal agencies.
"The U.S. Office of Personnel Management (OPM) manages the overall Federal executive personnel program, providing the day-to-day oversight and assistance to agencies as they develop, select, and manage their Federal executives."
https://www.opm.gov/policy-data-oversight/senior-executive-service/
I think we have a winner.