This has arisen from a nearby thread but does not warrant discussion there, and I am concerned that, while being only vaguely interested at the moment, I might be missing something fundamental that I may later regret.
My knowledge of Bluetooth may have some depth but it is not wide at all, and this HC-05 command, AT+DISC, is about as abstruse as you can get. I understand it is all about disconnection, but I have never seen an example of its use. Indeed an example is conspicuously absent from the data sheets, which further makes me wonder if I am missing the bleeding obvious. More to the point, I have always understood that HC-0x has two modes of operation - communications mode, and AT mode - and you cannot be in both modes at the same time, i.e. Bluetooth must be disconnected while sending an AT command.
So what is the sense in sending the AT+DISC command?