When deciding who should appear in the by-line of a Cochrane Review, it is important to distinguish individuals who have made a substantial contribution to the review (and who should be listed) and those who have helped in other ways, which should be noted in the Acknowledgements section. 

Authorship should be based on substantial contributions to all of the following four steps, as described by the International Committee of Medical Journal Editors (ICMJE) in the Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly work in Medical Journals. Authors must sign a licence for publication form that affirms all of the following:

• I/we have made substantial contributions to the conception or design of the work or the acquisition, analysis, or interpretation of data for the work.
• I/we have drafted the work or revised it critically for important intellectual content.
• I/we approve the final version to be published.
• I/we agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

The specific contributions should be listed under the section ‘Contributions of authors’. The list of authors can be the name of an individual, several individuals, a collaborative group (for example, ‘Advanced Bladder Cancer Overview Collaboration’), or a combination of one or more authors and a collaborative group; see section on group authorship {insert link to section}. Ideally, the order of authors should relate to their relative contributions to the review, with the person who contributed most should be listed first. Authors are encouraged to discuss the order of by-line authors early in the preparation of the Cochrane Review/ Protocol.

Authors may benefit from reading the report on how to handle authorship disputes prepared by the Committee on Publication Ethics before starting a Cochrane Review.