Bill Spight: Some years ago I coined the term, sente ko, which seems to be catching on. But looking at this classic example, I realize that it is actually ambiguous, as in ambiguous position.
If White takes the ko she raises the local temperature from 1/3 to 7/9 by threatening to take again. If Black replies at the temperature drops back down to 1/3. That means that this position is ambiguous, having both sente and gote properties.
(As always, we assume that the framing stones are alive.) This example is plainly ambiguous, as gains the same as , 1 2/3 points. It is not a sente ko because does not raise the local temperature.