There is a confusion in the understanding of this. When CIC says "any foreign addresses" it means foreign addresses after the person became a PR. Remember that many people land as a PR and leave Canada to live elsewhere temporarily, so CIC wants to know about those cases because you cannot have date gaps from the time you became a PR on your application. When it says "6 years", that would be for people that became a PR six or more years ago.
Rule 1. You need to list all foreign address you have lived at ONLY since you became a PR and for a maximum of 6 years. If you have not lived outside Canada since you became a PR, then you have no foreign addresses to list.
Rule 2. You do not have to disclose any foreign addresses before you became a PR. This is because time before becoming a PR does not count (at least not under the current law).
In this case, the argument arises because the PR seems to have lived in Canada since he/she became a PR, and therefore not having any foreign addresses to list since his or her landing.
