This comment seeks to point out that the timely review of capacitive biopotential measurements by Sun and Yu needs a clearer definition of capacitive electrodes that enables a more enlightening comparison of capacitive and dry conductive electrodes, which are two alternatives to wet electrodes for long-term applications. This, added to the ambiguous terminology in the description of system architectures, the oversight of some published results, and some potentially contradictory statements, makes the review inappropriate for the uninformed newcomer in spite of the large amount of references compiled and their broad scope.