NPC Code:
if (#s(#m)==hiddenstill||#s(#m)==hidden) {
client.savenick=#s(#n);
setplayerprop #n,;
} else {
if (!#s(client.savenick)==#s(#n)) {
setplayerprop #n,#s(client.savenick);
}
}
maybe something like that???
It shows the basic idea but i think graal should have a server option to do this automatically.