The IPC-2228 standard establishes the specific requirements for the design of rigid, flexible and rigid-flexible printed boards utilizing radio frequency (RF) and/or Microwave circuity and/or high frequency laminates where RF transmission lines and related passive metal layers are considered as distributed circuits, instead of conventional lumped circuit elements. The IPC-2228 standard is used to support product typically requiring materials meeting the requirements of IPC-4103 and fabricated to the requirements of IPC-6018. For use with IPC-2221 and other sectional design standards as applicable.