I don't know what your friend means with an ITP rating, but as far as I know second officers on the long range fleets (i.e. fresh from the academy) work as cruise relief pilots for the first years at KLM. They don't do any takeoffs and landings on the plane, but sit at the controls during cruise flight while one of the other pilots is resting.
I have never heard that they get several ratings and have only met guys flying a single type (i.e. either MD11, B747, B777 or A330). But I am always standing by to be corrected
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