US Patent 10410170 Propagating and expiring presentation information

Described is a system and method for propagating, synchronizing and expiring user specific information among multiple output devices. In some implementations, retention information is provided along with the user specific information and the output device and/or output device controller will determine when to expire the user specific information based on the retention information. In other implementations, the output device controller and/or output device may periodically request updates from other output devices, output device controllers and/or the inventory management system to determine whether to expire user specific information.