Since the publication of the O'Carroll et al. (1996) nomenclature for suicidology, there have been a number of published letters and articles, as well as an active e-mail dialogue, in response to, and elaborating upon, this effort to establish a standard nomenclature for suicidology. This new nomenclature has been presented on a number of occasions at both national and international meetings. In this paper we provide the background, rationale, and methodology involved in the process of revising the O'Carroll et al. nomenclature, based on the feedback and discussions that have ensued over the past 10 years. Those who have written and studied the phenomenon of suicide have not defined the term so simply ... how the word is defined has implications and large effects for statistics that are compiled on the official number of suicides, and for researchers, so that there is clear communication regarding what and who is being studied. Among writers in the field of suicidology there is no single common accepted definition ... the term suicide refers not to a single action but more broadly to a great many varied behaviors. For example, one can speak of suicidal thoughts, intentions, ideation, gestures, attempts, completions, equivalents. Thus far, no single term, definition, or taxonomy has served to sufficiently represent the complex set of behaviors that have been suggested as suicidal. A standard set of terms and definitions arc greatly needed to advance the science of suicidology and aid communication and understanding of the field.
