Dear who1074,
If applicant has employment history with large multinationals, then arranging reference letter in required format may become a difficult task sometimes. For example, my previous company refused to provide reference letter replying that they have already provided experience letter. I didn't request reference letter from my current employer as I didn't want to disclose but I am 100% sure that they are not going to provide reference letter in the required format too. Mostly, companies refuse to write down job duties & responsibilities on such letters. In such cases, written explanation along with the alternative proofs will serve the purpose as per NOTE on the first page of Document Checklist. Such written explanation along with alternative proofs will make your application complete.
In my case, I have 3 employment histories including the current employment and I couldn't arrange reference letter for any of these employments. I provided written explanation along with the alternative proofs such as experience letters, offer letters, salary slips, contracts, bank statement of salaries account, work permit visa etc. On my work permit visas, it is clearly written that it is issued for Mechanical Engineer. It will be quite straight forward for Visa Officer to understand if work permit is issued for a Mechanical Engineer, then Engineer must be performing tasks for Mechanical Engineer for such large multinationals.
Just to conclude, it is always best to send all forms and documents in required format but CIC has given the alternative options in case some documents are unavailable.
