Rigorous peer review is a vital part of the publishing process at Highlights of Sustainability. Reviewers who perform an invaluable service to the scientific community are essential to ensure the quality of papers published in Highlights of Sustainability.

A single-blind peer-review process is applied for all manuscripts (except for non-peer-reviewed types) submitted to Highlights of Sustainability. During the peer review process, reviewers know the identity of authors, but authors are not aware of the identity of reviewers.

Authors and reviewers are given the choice to participate in Open Peer Review. In such cases, authors can choose to publish all review reports and their corresponding responses to the review comments alongside their paper. In any cases, the reviewers' identities remain confidential during the peer review process unless they choose to sign their reviews. If a reviewer signs their report, their identity will be disclosed after the final publication of the paper they reviewed.

Each manuscript submitted to Highlights of Sustainability will be assessed by at least two independent reviewers. The selected reviewers are based on their expertise, publication history, and/or past reviews for Highlights of Science journals. Review invitations are sent by email through the online editorial management system. Reviewers can click the link included in the invitation email to accept or decline the invitation, based on the manuscript title and abstract.

Reviewers should accept an invitation only if they have relevant and necessary expertise, do not have any conflicts of interest with respect to any of the authors and the manuscript, and can provide an unbiased assessment for the research within the time frame specified in the invitation email. Reviewers who accept to review a manuscript are expected to provide quality review reports and remain responsive throughout the peer review process, and maintain standards of professionalism and ethics.

Reviewers are asked to evaluate the manuscript to provide recommendation to editors on final decision-making and comments to authors on how to improve their paper. When doing the assessment, reviewers will also be asked to rate the English language, and check if the work meets the highest standards of publication ethics, i.e., the manuscript must be original, not be plagiarised, nor a duplication of previous work.

Overall Recommendation: Reviewers are required to submit an overall recommendation for each manuscript to help the editors on decision-making. These include Accept, Minor Revision, Major Revision, and Reject. Accept recommendations suggest that the paper is acceptable in its current form and requires no further corrections. If a reviewer has any additional comments, please submit a Minor Revision (manuscript requires minor changes) or Major Revision (manuscript requires extensive reworking or additional experimental work, and apart from exceptional circumstance, a maximum of one round of major revision is allowed per manuscript) recommendation. Reject recommendations indicate the manuscript is not suitable for the journal, or it has serious flaws.

Rating the Manuscript: Reviewers are asked to comment on the following aspects of a manuscript:

At the end of the peer-review process for a manuscript that passed the initial editorial screening and was sent out for external review, the academic editors (the Editor-in-Chief, members of the editorial board, or invited guest editors) will make an editorial decision based on reviewers' comments and their own judgement. For this reason, the editorial decision of a paper may differ from the one that a reviewer recommended.

One of the following decisions may be made by the academic editors:

Reviewers will be notified via email that a final decision of the manuscript they reviewed has been made. The decision and comments can be accessed through the online system.

Conflicts of Interest — Reviewers should provide impartial and objective assessments for the papers they are invited to review. Please notify the journal's editorial office of any personal, professional or financial conflicts of interest that may affect the impartiality of the review report.

Confidentiality — Reviews must be done in strict confidence. Manuscripts that are under review should not be disclosed to a third party. Reviewers should destroy the copies after submitting their review. Reviewers must inform the journal's editorial office beforehand if they wish to discuss the paper with a colleague.

Anonymity — Highlights of Sustainability applies a single-blind peer-review process. The review process is conducted anonymously. Please do not reveal any identity to the authors, either in the comments or in reports submitted via attached files.

Objective Comments — Reviewers should concentrate on providing an objective assessment of the work and should avoid making statements that could cause offence, are derogatory or potentially libellous.

Timeliness — Reviewers are asked to return the reviews within the time period specified in the invitations to ensure a high-efficient publishing service for the community. Please contact the journal's editorial office to request a possible extension when the review cannot be done timely.

Certificate of Review — Reviewers will receive an email confirmation for each review they complete. They are also free to request a personalised Reviewer Certificate at any time upon a final editorial status (the editorial office will inform reviewers the final status of the manuscripts they review) of a manuscript is reached.

Web of Science Reviewer Recognition Services — Reviewers are strongly encouraged to submit their review work to the Web of Science Reviewer Recognition Services (formerly Publons) for recognition. In order to do so, just simply forward the final acknowledgement email from the journal's editorial office to reviews@webofscience.com.

Reviewer Discount Vouchers — Highlights of Science will issue discount vouchers to reward the reviewing work by reviewers. Reviewers then can use these discount vouchers for their submissions to journals published by Highlights of Science to get a reduced APC.

Annual Acknowledgement — The journal's editorial office will publish an annual acknowledgement to reviewers who supported the reviewing work in that year.