Technical Requirements Document (TRD) is no longer in use and was replaced by the System Requirements Document (SRD)
A Technical Requirements Document (TRD) was a requirements document that was put together by the government that addressed technical level requirements for a system. It accompanied a Request for Proposal (RFP) and provided a better technical breakdown than the Operational Requirements Document (ORDs) which usually lacked the technical details required to identify system performance outcomes in a system specification. The TRD has now been replaced by the System Requirements Document (SRD).
In 2003, the TRD and ORD were phased out with the introduction of the Joint Capabilities Integration and Development System (JCIDS) process. The ORD were replaced by the Initial Capabilities Document (ICD), the Capability Development Document (CDD), and the Capability Production Document (CPD).