This report has been prepared for the EOSC Future project as part of task 10.2.1 "Widening EOSC awareness and engagement in underrepresented communities" which aims to help EOSC become more receptive and responsive to the needs and realities of various domain-specific research communities as users of EOSC by providing insight into the challenges and needs of researchers in disciplines which are not as well-supported or engaged in the pursuit of Open Science. The conclusions presented here emerged from a series of interviews, surveys, focus groups, and conference events over the course of the project conducted with representatives from the Research Data Alliance (RDA), a volunteer-led community 'building the social and technical bridges to enable open sharing and reuse of data.' Representatives spoke on behalf of various disciplinary communities that were perceived to be underrepresented in EOSC, as well as those that were felt to be better supported, because raising awareness about common challenges allows us to leverage successful solutions where they already exist.