I am new to MQTT (and home automation in general, I am much more in the systems and dev side), flashed a WiFi switch (Sonoff Basic), connected it to an instance of Mosquitto and Home Assistant and so far everything works fine.
When monitoring the Mosquitto bus, I see all kind of messages, such as
tele/hass1/LWT Online tele/home/room1/switch1/LWT Online cmnd/home/room1/switch1/POWER OFF
home/room1/switch1 which I defined on my WiFi switch, and the switch then sent some topics prefixed by
cmnd (command? that would be surprising as nobody manipulated the switch) and
tele/hass1/... is generated by Home Assistant.
Are there any standards or commonly accepted practices for the prefixes?
The MQTT documentation explains how topics are formatted but does not introduce any structure (except for topics beginning with
$) so I guess that, best case, it would rather be a best practice (or practice full stop).