WTF is only punches to the body, and olympic is only punches to the body however a strike has to have shuddering ipact to score (these are both full contact).
I've spoken to people who have fought in WTF (full contact) and ITF (touch contact) and they say their isn't any difference in the level of contact. Only differnece is ITF allows punches to the face. BTW one of the persons I spoke to is a sixth dan and has copeted at the world champs and several WTF tornaments (meaning he knows what hes talking about .