We are making the DUTP protocol specification publicly available to encourage adoption and interoperability across the lighting industry. DUTP is a purpose-built transport protocol that combines the low latency of UDP with the reliability guarantees needed for live lighting control. Key features include multi-universe packet batching, end-to-end encryption for secure remote relay, and seamless interoperability with existing DMX512, Art-Net, and sACN infrastructure. The specification document covers the packet format, handshake sequence, error recovery mechanisms, and guidelines for implementing DUTP in third-party hardware and software. We welcome contributions and feedback from the community.