Relishes

Relish is generally a combination of pickles and vinegar.  Within North America, relish is much more commonly used in Canada than in the United States on food items such as hamburgers or hot dogs. American-based fast food chains do not normally put relish on hamburgers even at their locations in Canada, whereas Canadian fast food chains (such as Harvey's) do have it as a regular option just like ketchup, mustard, etc. American-based fast food chains use regular pickles to a greater extent. If it is offered as an option at Canadian locations of American-based fast food restaurants (e.g. Wendy's), it is generally offered in individually portioned packets rather than added atop the burger. Restaurants, fast food franchises and sports stadiums in Canada prominently offer relish as a topping on hamburgers and hot dogs along with ketchup and mustard, whereas this is less common in most of the United States (although there is variation within the United States.)