Corrections

Errors that do not invalidate the main findings may be corrected through a linked, dated notice that identifies the article and describes the change. The original article remains accessible and is linked to the notice.

Retractions and expressions of concern

An article may be retracted when findings are unreliable, publication is redundant, research is unethical, peer review has been manipulated, or another serious breach invalidates the record. A retraction notice states the reason and responsible party when established, is linked bidirectionally, and leaves the article identifiable as retracted. An expression of concern may be used while a material investigation remains unresolved.

Version control

Substantive post-publication changes are not made silently. Notices receive stable access and, where appropriate, DOI or metadata updates. Minor typographic fixes that do not affect meaning may be documented internally.