I did not see any statement that nomination certificate we send to CIC needs to be original, but we should send original to CIC.
What i understood is if they did not mention copy then we have to send original. See Helpful hints http://www.canadainternational.gc.ca/buffalo/imm/quebec_prov_hints-conseils.aspx?lang=eng
A - Application package
Arrange the submitted documents in this order:
IMM 0008 Generic (Application for Permanent Residence in Canada) with fee attached
2. IMM 0008 Schedule 1 (Background/Declaration) for principal applicant
3. IMM 0008 Schedule 4 (Intent to reside declaration for Provincial Nominees)
4. IMM 0008 Schedule 5 (Intent to reside declaration for Quebec Skilled Workers)
5. IMM 5406 (Additional Family Information) for principal applicant
6. IMM 0008 Schedule 1 (Background/Declaration) for spouse and children aged 18 and over
7. IMM 5406 (Additional Family Information) for spouse and children aged 18 and over
8. Copies of bio data pages of passports for principal applicant and dependents
9. IMM 5476 (Use of a representative form) If a representative has been appointed
B - Supporting Documents
1. Representative covering letter if a representative has been appointed.
2. Copies of identity documents
(birth certificates, marriage certificates, divorce and custody documents)
3. Police certificates from each country or territory where you have lived for six consecutive months or longer since reaching the age of 18.
National police certificates
You may be instructed by the Visa Office to provide police certificates from U.S. states where you have resided for 6 consecutive months or longer since reaching the age of 18. Click here for state police certificate instructions.
4. Provincial Nominee Certificate (for Provincial Nominees)