It was agreed back in April 2013 that MQTT would only be referred to as MQTT and not MQ Telemetry Transport.
From the minutes of 25.04.2013 "Working draft, TC review of protocol naming: R. Coppen notes that there is an
inconsistency about the use of MQTT. He welcomes the TC view on naming. The
inconsistency is in what the letters MQTT stand for.
The TC agrees that MQTT should not be standing for anything"
There is one place in the spec at the beginning of the Abstract where it is still referred to as MQ Telemetry Transport, this needs to be changed to just MQTT.