Here is the link: http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=43&top=34
It is recommended to keep CIC updated about address/contact information in case any correspondence is required.
Just curious, if someone can share experiences about what a CIC/NDVO phone interview is like - number they call from, what sort of questions they ask, do they identify themselves from NDVO, is there a prior notice about phone interview etc?