Greetings! Wonder if anyone had any experience with working for an international organisation (NATO, the UN, OSCE) outside Canada and its implications to maintaining Canadian residency status.

Wonder if any of time spent with an int'l agency where Canada is a member would count for the purposes of maintaining PR in Canada (I believe it does not counts towards naturalization, but not sure about maintaining residency)

Grateful for any info about your experience and helpful precedents

There are a lot of case studies listed in the Canadian Immigration decision section. Each and every new Government brought in new amendments to the law and thereby covered those loop holes that existed then, which permitted a few to enter and gain permanent residentship after that. But they then closed all of the doors for the future entrants little at a time, only leaving a few for them to decide under the humanitarian grounds. That is how the progress was made and how we arrived at the present format.
Just to cite one here is a link:
http://www.karas.ca/publications/Hun%20eNewsletter.pdf
You can also Google and find a few more interesting links.
Also you are free to pursue your own requirements through the appropriate web sites and there are a few who do the research and provide you with pertinent answers and quote sections of the IMM act to follow to get more insight into the subject matter. But it might not help resolve the doubts that you have over night.

Good Luck.

Freddie.