I was watching the old episodes with the Doctor, Barbra, Ian and Susan. The episode was "The Keys of Marinus." I was trying to figure out the symbol on the back of Ian's robe. Knowing that he knows pressure points from the Aztec episode I theorized it has to do with the martial art that he knows. I asked a friend what martial arts use pressure points and he tells me aikido I seem to recall Ian mentioning this in another episode. We looked up aikido symbols and I think we have a match with the symbols on the back of his robe. I think its a picture of a phoenix on the back. I don't have a clear enough picture of the front to make out the characters but they look similar to the characters I see when looking up "aikido symbols" in google images.