That's you immigration number for life. It was printed in your pr card and now it's in your certificate of citizenship for reference. If you ask what kind of information it contains, wel... everything they have on you from the day you applied to immigrate to Canada until now.
[/quote actually I do not have a Pr card cause I am citizen by descent{,my parents lived in Canada and that's how we applied,so what kind of information can be now to me?today I tried that number and I saw that they received my application for sponsoring my husband.
thanks for the answer