MIL-C-17 is the government specification document used to standardize coaxial cables; it has been in use since the 1940’s. In the many revisions made to MIL-C-17 over the years, the familiar RG part numbers were superseded by M17 part numbers during the 1970s. The benefits of these more recent revisions are discussed under the following headlines.

BENEFITS IN USING MIL-C-17 COAXIAL CABLES
Revision E to MIL-C-17 was released in 1976 to better define the mechanical and electrical requirements for military coaxial cables. For 50-ohm cables, the most important changes were the addition of swept frequency measurements of both attenuation and structural return loss requirements (VSWR) to 22 different cables. Before this revision there were no VSWR requirements, and attenuation requirements were only given at two or three discrete frequencies.