CORTRE aims to establish a community-accepted reporting guideline for reproducibility studies, i.e., large-scale investigations evaluating the reproducibility of findings or entire fields. These studies are influential in shaping research policy and practice but currently lack widely accepted reporting standards. This project will bring together meta-researchers and guideline enthusiasts to collaboratively define an initial draft of reporting items and develop a study protocol, inspired by methods used for other guidelines (https://www.equator-network.org). Participants will be divided into methodologists, who will design the approach to reach community consensus, and topic experts, who will draft a preliminary list of reporting items. The guideline will be finalised post-unconference, following a pre-registered protocol and led by a core team composed of a subset of committed participants. The resulting guideline will support researchers, reviewers, and policy-makers in producing and evaluating reproducibility studies with consistency, fostering more robust and transparent meta-research.