Specify the finished two-port assembly, not only bulk cable attenuation. State continuous frequency bands, overall length, both connector interfaces and calibrated reference planes. Set maximum insertion loss from S21 and separate input and output return-loss or VSWR limits from S11 and S22.
Name temperature, routing and bend state, frequency resolution and production tolerance. Include adapters or fixtures only when they are part of the delivered boundary; otherwise calibrate or de-embed to the mating interfaces. Preserve complex data when phase, delay, gating or cascade analysis is required.
Acceptance should document calibration, connector inspection and torque, cable support, remate repeatability, uncertainty, serial number and drawing revision. A typical cable attenuation curve or screen capture cannot qualify the complete assembly.