A “yes” answer to 3(a) or 3(b) means that active pre-1957 MS was used to establish eligibility
                  to the award, and that service in that period is not creditable for SS purposes. Generally,
                  these items will be answered “yes” if the employee retired from the Civil Service under an immediate retirement for
                  age or service. MS never is used to establish eligibility to disability annuities,
                  or to deferred annuities payable under the CSRA for separations from the Federal Civilian
                  service effective April 1, 1948, and later.