Travelling to players

Blue, Assassin of Rura Penteto Everyone

the other day i travelled to a friend who was in The abyss of souls. I was testing out my travel power. I was met there by Nostradamus who was displeased with my action. He was kind enough to give me a chance and took no action against me . I do not w ant to offend anyone any more. Could someone give me a few guildelins about using my travel power (eg: point bracelet x) . Is it a case of knowing where the person is before beaming to him . Which areas are off limits. Thanks