The objective of the work on Command, Control and Communication, Spectrum and Security (C3&S) is to maximise the relevance of its outputs to all classes of UAS and achieve alignment with regulatory directions and operational needs. The main technical deliverables (MASPS and MOPS) tactically address the needs of Certified RPAS for the C2 Link, Spectrum Management and Security. A series of technical reports will provide complementary guidance on communications, spectrum management and cybersecurity applicable to the other UAS categories.