I do it, but others have said no. Depends whether you're a rule breaker or not ;-) I type in all 3 order numbers as the reference (except the very last digit as it doesn't fit) then on the dispatch note inside the parcel I write all 3 order/item numbers. Never had a problem. I refuse to follow Q's stupid imposed rules. No other company would charge postage and return per item. If they didn't like it they could contact me to tell me not to do it.