Well, if you have already submitted your move, and they haven't viewed the game yet, you can go back to it and click "Edit" near the top, and add a message. If they have already viewed the game (but not yet played) you cannot do that.
(esconder) Se passar com o rato no ícone de nível de inscrição de um jogador, surge um pequeno texto com os seus detalhes. (pauloaguia) (mostrar todas as dicas)