This dataset is a component of the Polonez Bis 1 project No. 2021/43/P/HS2/01395, co-funded by the National Science Centre and the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 945339, headed by Katarzyna Janic as Principle Investigator, from October 1, 2022, to September 30, 2024, at Adam Mickiewicz University. The foundation of the dataset, including its methodological and theoretical framework, was established earlier during a project funded by the European Research Council under the European Union's Horizon 2020 research and innovation program (grant agreement no. 670985), with Martin Haspelmath serving as the Principal Investigator. The work on this dataset was subsequently advanced and completed during the initial phase of the Polonez Bis 1 project, during which Katarzyna Janic and Nicoletta Puddu (external collaborator) contributed to populating the dataset. They entered data based on contributions from 27 language experts submitted to the edited volume Reflexive Constructions in the World's Languages, which they co-edited with Martin Haspelmath. This dataset forms part of the Polonez Bis 1 research project and remains subject to further adjustment. Should you observe any inconsistency, please contact Katarzyna Janic at Katarzyna.Janic@amu.edu.pl.