Prospective registration of medical research in publicly accessible domains such as ClinialTrials.gov (https://clinicaltrials.gov/) or the Open Science Framework (OSF; https://osf.io/), can increase study transparency, align evaluated health outcomes, and reduce the risk of unnecessary duplication as well as avoidable research waste. [1, 2] In the field of psychology in the past 5 years, researchers have also endorsed registration of research plans in a time-stamped, online repository prior to conducting the study, to improve replicability and credibility of psychology research – which they termed preregistration. [2, 3] Of note, the terms registration and preregistration have been used interchangeably for almost a decade, and the intended distinction between the two terms is largely unknown. [2] Similarly, registration of systematic reviews is a highly effective form of reducing unplanned duplication of systematic reviews, by allowing researchers to first check if there is already an existing review that addresses their topic of interest, prior to planning a new review. [4, 5] Prospective registration of systematic reviews can also reduce the potential for methodological and reporting bias, for instance by prospective subgroup definition or limiting the influence on decisions to include or exclude certain items, in order to shape a review in favor of the desired conclusion. [4, 5] In addition to the methodological benefits, registration offers advantages to many stakeholders (i.e., funding organisations, guideline developers, journal editors, peer reviewers), as well as the public. [5] For instance, if utilized widely, the registration process can limit unintended duplication and avoidable waste of financial resources, aid in the planning and timing of guideline updating and development, assist as a tool to augment peer review (already at protocol stage) and limit reporting biases. [5] The first international prospective register of systematic reviews (PROSPERO) was launched in February 2011, as a database to register SRs at inception. [1] Prior to 2011, only select high quality organisations, such as Cochrane, Campbell Collaboration and Joanna Briggs Institute, disseminated protocols for ongoing SRs, which although producing a minority of all published SRs, are considered the ‘gold standard’ of reviews [1]. While recent studies have indicated that the uptake of registration of systematic reviews in PROSPERO has increased rapidly since 2011 [1], there are now more options for dissemination of systematic review protocols, for instance, open access journals like Systematic Reviews and open data repositories like the Open Science Framework (https://osf.io/registries/discover?q=protocols). References: [1] Page MJ, Shamseer L, Tricco AC. Registration of systematic reviews in PROSPERO: 30,000 records and counting. Syst Rev 2018;7(1):32. [2] Rice DB, Moher D. Curtailing the Use of Preregistration: A Misused Term. Perspect Psychol Sci 2019;14(6):1105-8. [3] Nosek BA, Ebersole CR, DeHaven AC, Mellor DT. The preregistration revolution. Proc Natl Acad Sci U S A 2018;115(11):2600-6. [4] PROSPERO: What is registration?, https://www.crd.york.ac.uk/prospero/#aboutpage; 2021]. [5] Stewart L, Moher D, Shekelle P. Why prospective registration of systematic reviews makes sense. Syst Rev 2012;1:7. [6] Booth A, Mitchell AS, Mott A, James S, Cockayne S, Gascoyne S, et al. An assessment of the extent to which the contents of PROSPERO records meet the systematic review protocol reporting items in PRISMA-P. F1000Res 2020;9:773.