Yup here it is:
http://www.cic.gc.ca/english/resources/tools/perm/express/intake-complete.asp
Document requirements
For the applicant’s current country of residence, the police certificate must have been issued no more than six months before the submission of the e-APR.
For countries in which the applicant no longer resides, the police certificate must have been issued after last time the applicant lived in that country.
Police certificates are required up front and are mandatory for each country (except Canada) where an individual has lived for a total of six months or more. This instruction is for the purpose of the completeness check under section R10. However, it is always at an officer’s discretion to request a new or additional police certificate.