The content of Table 1 in the Gerard and Walker article will be updated and corrected for future publications. About certification, clinical nurse specialty practice is defined by many factors including emerging health needs of society, expanding knowledge, and changing cultural and geographic demographics. Specialty practice should not be defined a priori by a certification examination. The National Association of Clinical Nurse Specialists has identified over 40 specialty areas of clinical nurse specialist practice. Certification examinations, or other measures of competency, should be developed and revised in response to practice; therefore, there are many specialty programs that do not have corresponding certification examinations.