The Interactive Advertising Bureau of Canada announced Monday that it has begun to standardize online ad sizes for Canadian sites. The "Canadian Universal Ad Package" guidelines are nearly identical to those published by the U.S. arm of the IAB. One minor difference is that a smaller ad size-- 180x150 pixels--is not included in the Canadian guidelines because it doesn't often appear on Canadian sites. Animations also face a new restriction--they can only loop three times or be 15 seconds long, whichever is shorter. The U.S. guidelines place no restriction on looping ad animations; they simply require that they be shorter than 15 seconds. IAB Canada will release guidelines for rich media and video-streaming ads later this year.