The present invention provides for the ranking of messages for presentation to a user based on user behavior with respect to previous messages received from ranked communication endpoints. According to an embodiment, the annealing vessel has a dual chamber structure, and potentially toxic, flammable, or otherwise reactive gas is confined in an inner chamber which is protected by pressures of inert gas contained in the outer chamber. The lighting board is a combination of plastic optical fibers with letter fonts or patterns or different structures. A receiver demodulates the received signals and applies multi-input, multi-output demapping to estimate the BICM encoded bitstream.