This EOSC co-creation project analysed the innovative capabilities of the new domain-agnostic Data Documentation Initiative-Cross Domain Integration (DDI-CDI) specification (currently in review and to be released in a first production version in June 2021). The project examined how the specification could be applied to much-needed search and data integration functions within EOSC. It did so through a structured consultation with a range of experts and initiatives as detailed below. The main output is a significant report ‘The Role of DDI-CDI in EOSC: Possible Uses and Applications’ https://doi.org/10.5281/zenodo.4707263 that details the substantive exploration and findings from this process. A number of specific and important issues were explored, and examples given of the uses and applications of the specification for EOSC. The report makes recommendations for EOSC, EOSC stakeholders and for the DDI Alliance as the curator of the DDI-CDI specification. This document describes the approach taken in the investigation and analysis of how the DDI Cross Domain Integration (DDI-CDI) specification could be used to support the EOSC data-sharing infrastructure. It describes the process for the investigation and identification of recommendations, and enumerates and describes the meetings, interviews, and events in which the authors of the report took part. This work was supported by the EOSC Secretariat. EOSCsecretariat.eu has received funding from the European Union's Horizon Programme call H2020-INFRAEOSC-2018-4, Grant Agreement number 831644.