This statement is generic for many countries because those countries need some explanation why you need a police certificate.
You have got an ITA. And after you submit your application, it says you need a police certificate. You have two choices, you may place a PDF saying those countries need official request from CIC to issue a police certificate. And submit your ITA. Or you may take a printout of your ITA letter and the print of the form where it is saying you need saudi certificate and go to your embassy to get a NOC to start your PCC process. Most often than not your embassy will issue you a NOC for Saudi PCC without even asking what is your purpose.
The cons in the second way is if you procure the Saudi PCT quite early, CIC may ask you to get that PCC again.
Hope I make it clear.