How do I find my thermostat's MAC ID and MAC CRC for online registration?

The MAC ID and MAC CRC will display in the message center of the thermostat, and these alphanumeric codes are also included on a card packed with the thermostat or on the back of the thermostat (visible when removed from wallplate). Each thermostat has unique MAC ID and MAC CRC codes needed for registration at mytotalconnectcomfort.com.