Author Contribution Statements
Authors are required to include a statement of responsibility in the manuscript that specifies the contribution of every author. The level of detail varies; some disciplines produce manuscripts that comprise discrete efforts readily articulated in detail, whereas other fields operate as group efforts at all stages. Other equal contributions are best described in author contributions statements. Corresponding authors have specific responsibilities (described below).
For example, "AB and CD wrote the main manuscript text, and EF prepared figures 1–3. All authors reviewed the manuscript."