Expressions of Concern (EoC) have been variously used across the industry either as an “update notice” to flag serious unresolved concerns while further investigation is taking place or used as an “outcome notice” where there are concerns about a publication but conclusive evidence about the reliability of the publication cannot be obtained.

In recent times, there has been development in the area of post-publication amendment – notes. Notes have typically been used on articles where the journal/publisher needs to acknowledge or explain a situation and another amendment type is not appropriate. Notes can take the form of a "alert notice" to acknowledge where a concern has been raised about an article but the outcome is not yet available or may take some time. However, notes can also be used as an "outcome notice" too, to highlight issues that are relevant to a readers interpretation of the work but do not meet the criteria for a Correction, EoC or Retraction.

The jury is still out on the use of Notes versus Expressions of Concern, or both, we are seeing heterogeneity in their use in terms of technical and resource considerations. But any experimentation and innovation to speed up the challenges of post-publication correction has to be encouraged.

Source https://publicationethics.org/news-opinion/continuing-conversation-post-publication-amendment