IPC-4203B establishes the classification system, the qualification and quality conformance requirements for dielectric films coated with an adhesive on one or both sides, which are to be used as cover material and/or bondply for flexible printed circuitry, as well as supported or unsupported adhesive films to be used in the fabrication of flexible printed circuitry. IPC-4203B does not cover non-flexible adhesives designed to be used in the rigid board areas of rigid flex constructions, which are covered in IPC-4101. Materials such as liquid-applied covercoat (see 3.1.8.3) are covered in IPC-SM-840 and are excluded from this document. 38 pages.