This standard establishes the classification system, the qualification and quality performance requirements for flexible metal-clad dielectric materials to be used for the fabrication of flexible printed circuitry and flexible flat cable. It encompasses 12 specification sheets that result from the combinations of various copper foil claddings; a polymer base dielectric selected from at least two polyesters, multiple polyimides or liquid crystal polymers; and at least seven versions of polymer adhesives as well as adhesiveless bonding agents. The net result of these material combinations provide the industry with suitable clad, flexible dielectrics for fabricating flexible printed circuitry interconnections. With Amendment 1, this document now addresses how to utilize legacy designs that refer to earlier, out-of-date material designations. 53 pages. Released October 2013.