According to the recommendations of the ICMJE (International committee of medical journal editors) authorship must be based on 4 criteria:
Persons who do not meet all 4 criteria of authorship should be listed in the "Acknowledgements" section. These criteria are designed to ensure that authorship status was granted to those who are trustworthy and can take responsibility for the published work. These criteria should not be used as a means of suspension from colleagues authorship satisfying other criteria, by depriving them of the possibility to meet the criteria 2 or 3. Therefore, all persons in charge of the 1st criterion, should be able to participate in the processing, writing the first version of the manuscript and its final approval for publication.
The authors (not the magazine, which takes the article) have to jointly set that all persons mentioned in the list of authors, meet all four criteria. It is not the task of editors to determine who meets or does not meet the authorship or authorization related to authorship conflict. If you can not reach an agreement about who can be qualified as an author, you should ask for a dispute resolution institution where the work was done. But not the editor. If the authors are asked to remove or add the author after the presentation or publication of the manuscript, the editors should receive appropriate explanations and signed statement of consent of all the authors listed in the list for the requested change, as well as from the author whose name is to be removed or added. Leading the correspondence author has primary responsibility for communicating with the magazine during the presentation, review and publication of the manuscript, and it also usually provides the correct implementation of all the administrative requirements of the magazine, fo example, providing details of these authors, obtaining the approval of the Ethics Committee and registration clinical trial documents collection forms and statements of conflict of interest. It should be available throughout the process of submission and review of the manuscript for a timely response to the issues of the editorial board, as well as after the publication in order to respond to criticism of the work and to provide on-demand version of any information and additional information in case of questions on the article after its publication. If the research is being conducted by a large group, ideally, the group must decide who is the author, before the start of and confirm the decision prior to the submission of the manuscript magazine centuries. All members of the group included in the list of authors must meet all 4 criteria of authorship, to assume public responsibility for this work and have full confidence in the accuracy and integrity of the work remaining members of the group of authors. They must also fill out the forms relating to conflict of interests.
Other participants in the work, do not meet all the 4 above the authorship criteria are not indicated as authors, but they should be thanked. Examples of activities that can not be considered a sufficient basis for the attribution, are the attraction of funding sources, the overall administrative support, assistance in writing, editing, proofreading. Individuals whose contributions do not qualify as authorship, we can express our gratitude - individually or all together as a group under a single heading. For example, "the study participants." In this case it is recommended to ask the editors by the corresponding author, to obtain written permission to mention in the acknowledgments of all persons who have expressed gratitude.