The purpose of this article is to encourage and help inform active discussion of authorship policies among members of scientific societies. The article explains the history and rationale of the influential criteria for authorship developed by the International Committee of Medical Journal Editors, examines questions about those criteria that emerge from authorship policies adopted by several U.S. medical schools, and summarizes the arguments for replacing authorship with the contributorguarantor model. Finally, it concludes with a plea for scientific societies to play (...) a prominent role in the ongoing debates about authorship and the alternatives as part of their efforts to encourage ethical conduct among their members. Whether or not scientific societies develop authorship policies of their own, they should undertake vigorous educational efforts to keep their new members adequately informed about the importance of authorship practices in ethical scientific research and publication. (shrink)