The manuscript presents a new article type (LESSONS), dedicated to scientific errors, limitations and null results - topics frequently absent in classic scientific literature. It refers to several peer-reviewed articles addressing these topics, which showcase the impact of a positively biased publication culture, as well as the scientific value of reporting errors, limitations and null results. The article properly states the need and advantages of this type of article. I warmly congratulate the authors on this initiative.

Before publication, I would recommend considering the following suggestions:

L.117-124: In this part of the text, the authors give examples of discontinued journals dedicated to the same topic. In my view, it would be helpful to reflect on the potential causes and to state what will be done to avoid a similar ending for the LESSONS article type.

L.222-223: the authors highlight that limitations, errors, etc. (i.e. LESSONS) have been published before in "regular research articles", together with "substantial new results, advances".  In my view, the advantage of publishing this type of results in a LESSONS article type in comparison to a "regular" article type is not clearly stated. Are LESSONS articles a temporary need while the publishing culture does not change? If not, this should be clearly stated.

Chapter 3: I think it would be worth adding to this section the answer to "When to write a LESSONS article". In my perspective, a researcher will continue investigating a problem until the "substantial new result" is found. At that time, they might prioritize writing a "regular research article" in comparison to a LESSONS article. There are sufficient arguments in the manuscript supporting the writing of a LESSONS article. However, current career incentives might pressure researchers to move on to the next finding instead of documenting the LESSONS from their just published work. I think it would be useful if the authors could acknowledge and elaborate on these challenges and motivate the need to timely document the discovered errors and shortcomings.

L.240, 258, 358, 360, 362: capitalize "report(s)" for consistency.

L.240-241: introduce ACP after "article processing charges" just for clarity.

L. 250, 359, 361: capitalize "post(s)" for consistency.

This manuscript introduces an article type titled LESSONS, which is to be included in some EGU publications moving forward. LESSONS are actually two types of articles but both types aim to overcome the bias towards positive-results publishing. The manuscript details the motivation behind this initiative as well as outlining article scope and format and guidelines for writing, editing and reviewing LESSONS articles. In the introduction, the authors provide some compelling reasons as to why this type of article will be valuable to researchers moving forward. It is clear that there is definitely room, and need, for LESSONS articles in the scientific publishing sphere. Well done to the authors for this optimistic initiative and I look forward to reading some of the LESSONS articles in the future.

I’ve provided some comments below as suggestions for very minor improvements to the finished manuscript.

Section 1.1: Have the authors considered whether certain groups of researchers are more likely to benefit from writing and reading LESSONS articles than others? For example, LESSONS articles might be more adopted by early career stage researchers, or researchers operating within limited resource environments since they are less likely to be able to ‘afford’ mistakes and errors compared to senior researchers or those with stable funding. And from this, are there certain groups of researchers that will be more likely to submit LESSONS articles compared to others? The authors could speculate on this using abstracts submitted to the BUGS session later mentioned in the article. I do understand that this information might not be out there to include in this section, but it could offer useful insight if that’s possible.

Line 111 – 113: The inclusion of the BUGS sessions at the General Assembly provides good context for the need for LESSONS articles. The authors could include some basic information such as number of abstracts submitted to BUGS sessions in previous years, or number of posters/presentations etc to strengthen this context.

Line 117-124: I agree with the comment from another reviewer here. As well as offering some reflection on why this topic has not been adopted successfully in previous attempts, it could be useful to include some details as context. For example, if the ‘Black Swans’ manuscript category received no submissions, how many submissions did other manuscript categories receive in contrast? Is there any information about whether the submission process for this category was different in any way to other categories?

Section 4: I’m curious about the review process for the LESSONS articles and it’s great that the authors have a specific section on this. One of my concerns about the LESSONS articles is not the articles themselves, but that a positive result bias may also translate to a positive result review bias. Can the authors speculate as to whether it would be more difficult to attract reviewers for LESSONS articles compared to other research articles? Perhaps there is information about this from some of the other publications previously mentioned earlier in the article. Given that one part of peer review may be to suggest to authors different ways of analyzing data or improving methods, is there a risk with LESSONS articles that during the peer review process, the ‘error’ that the article is based on is actually solved? And how does that affect the relevance of the article submitted? All of this is just to say that the section on editing and reviewing could be strengthened by the authors having a bit of a discussion about how the peer review process for a LESSONS article may differ and how these differences will be tackled by reviewers.