Authorship which is important to the grant support, academic promotion and reputation of the scientists and their institution should be determined by how genuinely they contribute to each article. The International Committee of Medical Journal Editors (ICMJE) has recommended that authorship credit should be based on substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; drafting the manuscript or critical revising it; and ultimate approval of the version to be published. Interpretation of the respective contributions of individual authors is not possible from order of authorship. The corresponding author should certify that all authors fulfill standards for authorship and prepare a brief written description of their contribution to the manuscript. This information provides an appropriate context for the readers of the articles to be able to interpret the authors’ roles correctly.