This specification covers the requirements for clad and unclad plastic laminate and bonding layer materials to be used for the fabrication of printed boards for microstrip, stripline, and high speed digital electrical and electronic circuits. In addition to updated testing parameters, inspection lot requirements, revised visual acceptance criteria, this revision incorporates a new specification sheet format for new materials that provides both mandatory (e.g., Df and Dk) requirements as well as "loose" requirements (e.g., thermal conductivity and moisture absorption) that can be certified to or called out on fabrication drawings. This new classification format allows for a reduced number of material specification sheets.