Ct should have knife shape middle bar that curves back with a pointy tip, 2nd middle bar has no bulge and is parallel or slightly curves toward the middle bar, the last 2 bars on the tail should have the middle bar thicker than the last bar and not fully extended to the bottom, and the last tail bar is thinner than the middle tail bar and curves along the edge of the tail fin
addisonlee25 shows a nice example of a CT (though I would like to see a more curvy and pointy mid bar, but I love the creamy gold color!!!)
Of coz, not saying every CT will have all of the above traits, but I will personally pass on a CT that does not
Indo usually will have 2 straight bars of the same thickness fully wrapping the tail