移民加拿大:工作證明信必須是original 嗎?

Appendix A Checklist: 一開始說: send photocopies document except the police certificate, which must be originals. 但在第七項work experience 又說:Original and up-to-date letters of reference from your past and current employers.
有點犯糊塗>

請教有經驗的大俠: 到底複印件行嗎? 謝謝!