Publishing correction is considered if minor errors that do not affect the results, interpretations and conclusions of the published paper/content are detected. Retraction is considered if major errors and/or mis-conduction that invalidate results and conclusions are detected.
An expression of concern is considered if there is evidence of research or publication misconduct by the authors; there is evidence that the findings are not reliable and institutions of the authors do not investigate the case or the possible investigation seems to be unfair or nonconclusive.
The guidelines of COPE and ICJME are taken into consideration regarding correction, retractions or expression of concern.