Originally Posted by
San Gottardo
You could also try to pull your reservation up on the KL website. They have a field for KTN. If it shows there, you should be ok.
I don't think I've ever seen my KTN input on my PNR on Delta.com carry over to the KTN field on KLM.com. No idea what would happen if you just left the DL one but didn't put anything in the KLM field.