Huge amounts of research data stored in a multitude of research data repository platforms can often only be used by a comparably small audience. On the one hand, this is caused by differences in semantics, underlying data models and metadata schemas, whose complexity and number prevents scientists from taking advantage of them. On the other hand, a lack of interoperability between research data repository platforms causes research data not to be used to their full potential. The goal of the RDA Research Data Repository Interoperability WG (RDRIWG) was to achieve consensus on an adoptable approach to facilitating research data repository interoperability for a defined set of initial use cases. The following document presents final recommendations the members of the RDRIWG have agreed on. It describes a general exchange format based on the well-known BagIt specification complemented with BagIt Profiles, another specification defining how to describe the internal structure of BagIt-based packages. In order to achieve a basic level of interoperability with regard to the content of such exchange packages, the WG members have agreed on recommending to include DataCite metadata in each package. The presented recommendations document describes the exchange format itself together with adoption guidelines and information about related efforts. In addition, early adoptions are publicly available at GitHub and referenced within the document.