Corrections
A correction may be issued when an otherwise reliable article contains an error that materially affects interpretation, indexing information, author identification or another significant element.
Retractions
An article may be retracted where evidence demonstrates that its findings are unreliable because of major error or misconduct, or where serious ethical or publication-integrity concerns invalidate continued reliance on the work.
Retraction notices shall remain openly accessible and linked to the affected article. The original article record should remain identifiable as part of the scholarly record rather than silently disappearing.
Expression of Concern
An Expression of Concern may be issued where credible concerns exist but an investigation has not yet reached a sufficiently definitive conclusion.