chef,
You must have indicated in your fingerprinting card, "Canadian Immigration" under Reason fingerprinted. That should be good enough. As you can order FBI PCC for personal review as well, so it doesn't matter whether you indicate any separate evidence or not. However, if it was an expedite request for a definite date, then it would be important to indicate the reason in the Cover Letter as well as outside of the envelope and then put in any supporting eveidence that you can. In any case, putting any evidence is your choice and not mandatory at all.
You must have indicated in your fingerprinting card, "Canadian Immigration" under Reason fingerprinted. That should be good enough. As you can order FBI PCC for personal review as well, so it doesn't matter whether you indicate any separate evidence or not. However, if it was an expedite request for a definite date, then it would be important to indicate the reason in the Cover Letter as well as outside of the envelope and then put in any supporting eveidence that you can. In any case, putting any evidence is your choice and not mandatory at all.