@ this moment there seems some confusion of what the exact format of the HH field should be, if you look @ the specifications it states:
HH - string - Hub Host address ( DNS or IP )
What means a simple URL or IP no port given
If you look @ the example given alto it indicates also the port suffix to be included.
So what is the real spec ?
The last seems logic besides 1 point , if this HH is going to be used to inform a hublist about a address change , why not send the complete qualifyed ADC address like:
(and maybe this field could then maybe 1 day be used to autoupdate the clients favorites )
That way it could be realy used to change a adc hubs address to any ADC(s) compatible address.