Abstract: Differences between the existing definition of calibration and the activities of calibration laboratories have led to problems in the expression of calibration results, the measurement uncertainty of calibration results, calibration and measurement capability (CMC), and the expression of measurement uncertainty in calibration certificates. These issues result in incorrect expression of calibration results or failure to achieve desired outcomes in the application. Using examples, this paper illustrates the negative effects of these problems on the metrological confirmation, examination of measurement standards, and laboratory's CMC. Based on the definition of calibration, this paper discusses evaluation methods of calibration results and measurement uncertainty, and proposes suggestions for expressing calibration and measurement capabilities, results, and measurement uncertainty in calibration certificates.