All options to retun data about conference

So I’ve just implemented a custom module. I am playing around with the features in .lua and noticed you can return the name of the room with :

function (event)
local room =;

Can somebody please supply me with all the viable options of event.(option)?
My current goal is to return just the explicit name of the room that the user has entered.

Not sure what event is that, but if its something coming from prosody, just search the event name where it is fired in prosody code and you will see all the objects passed in the event.