Hundreds of scientific journals use author–number systems. They all follow the same essential logic (that is, numbered citations pointing to numbered list entries), although the trivial details of the output mask, such as punctuation, casing of titles, and italic, vary widely among them. They have existed for over a century; the names "Vancouver system" or "Vancouver style" have existed since 1978. The latest version of the latter is "Citing Medicine", per the "References > Style and Format" section of the ICMJE Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals. These recommendations, the "Vancouver Convention" and "Vancouver guidelines", have a much broader scope than only the citation style: they provide ethical guidelines for writers and rules for co-authorship in scientific collaborations to avoid fraud. The Convention further entails compliance with the Helsinki Declaration, and research projects must be recommended by an independent ethics committee.