I included a cover letter on mine, I put it in our application after the barcodes and checklist.
The cover letter I believe is a good idea because you can explain ahead of time any issues a visa officer may see that may raise questions, That aren't just about your relationship.
Here is mine as an example of why I think it is helpful to the officers, and how I wrote it up.
Out of Canada Sponsorship Visa Cover Letter
Name of Sponsor
Birthday & Address of Sponsor
Name of Sponsered Spouse
Birthday & Address of Sponsored Spouse
APPLYING UNDER SPOUSAL SPONSORSHIP
To whom it may concern,
I _______________ a Canadian Citizen by birth. I am filing these forms in order to sponsor my husband ________________ under the Family Class Sponsorship.
Below are some facts that will help verify some questions or concerns you may have withing the application.
(1) Names- My husband has a different name on his birth certificate than the name that everyone calls him, so on our chat logs and skype calls his name is John. But on his official documents, it is his birth name. Visa officers might believe the chat logs do not belong to him if I don't explain how he has two names.
(2) Financial- I was in my husband's country during this process unemployed, so I let them know I have jobs waiting in Canada to be able to finance him. (This is good to read before they look at my income for the year so they aren't confused about why it is so little because I moved half-way through the year)
Relationship Outline
Write a brief description on how you met, no need to be detailed in the cover letter because it is another question in the application.
Plans up arrival in Canada
Write a description of where you will live, work/study etc.
Thank you for taking your time to consider our sponsorship.
I know it isn't necessary but if you have little issues like I did that weren't just pertaining to the relationship part of the application then a cover letter clears that all up before they get started, and they won't have to write notes on things you already explained that they might have had to read through pages to find out answers too. It wouldn't hurt you to write it out if it makes you feel better about it. I believe the will look at a cover letter seeing as it is the first thing they will view that isn't a generic application page, at least you will have comfort knowing you explained everything that could raise questions.
Hope that helps
This sounds very good. helps much! but i confused about bar codes, where do we put these? i was thinking had to paste or tape them on the envelopes? and was your cover letter in an envelope that contained all the application forms and in sponsor or applicant forms? thank you!