Ok, I'm thick , what do you mean by 'sending a stake back to issuer' ?. Do you mean you have to make your self an account number on client and then send that number as a pm from btt account to an account somewhere?
He's referring to people who have NEMstake token on the NXT Asset Exchange. The "issuer" means the asset issuer, or the person responsible for handling NEMstake on the NXT AE who originally distributed them in the first place.
I suppose by matching your NXT address with a NEM address they can see how many stakes you sold back to the issuer and therefore how much NEM you are due after launch.
Ok fair enough but I was just talking about normal initial stakes.