The recent deployment of large communication satellite constellations has significantly increased both electromagnetic emissions and reflections from in-orbit spacecraft, impacting ground and space-based astronomical observatories. This study will therefore seek to develop emission and reflectivity recommendations applicable to future satcom satellites, balancing the needs of both astronomers and satcom operators and manufacturers. The activity will include consultation with stakeholders from both communities to generate mutually acceptable recommendations for achievable and verifiable requirements, as well as a technology development roadmap for any new capabilities implied.