If you are listing on ebay.ca the Canada English will show on your screen just to indicate that you are logged into ebay.ca, and not ebay.com It is also an icon that enables you to change from English to French if desired. (If you click on the Canadian flag, Francais will appear.)
It does not refer to differences in spellings, or change the letters of the words that you have chosen to put into your listings, for example, color/colour, the way a Spell Checker will automatically change particular words.
This is my understanding of it anyway.
