Ghost authors:This phrase is used in two ways. Itusually refers to professional writers (often paid bycommercial sponsors) whose role is not acknowledged.Although such writers rarely meet ICMJE criteria, sincethey are not involved in the design of studies, or thecollection or interpretation of data, it is important toacknowledge their contribution, since their involvementmay represent a potential conflict of interest. The termcan also be used to describe people who made asignificant contribution to a research project (and fulfilthe ICMJE criteria) but are not listed as authors. TheICMJE guidelines clearly condemn this practice and statethat ‘All persons designated as authors should qualify forauthorship, and all those who qualify should be listed.’