Personally, I can proudly state that I loathe and detest any sport - ANY SPORT AT ALL - that implies the use or abuse of a ball of any shape, by however many people who should know better, but yourdictionary.com suggests that the word "soccer" is derived by the

"shortening & alteration from association football"

This being the case, only Association Football (whatever the hell THAT is) should be called soccer, and therefore anything ELSE can be called football - whichever part of the body hits the damned ball. And that includes Aussie Rules, League, et al. In my young day, you only ever heard of playing fitba' or rugby and that was that. Those of my persuasion just ran for cover.