Char

No, not the volcanically active homeplanet of Zerg race from StarCraft...

(image from http://starcraft.wikia.com/wiki/Char)

... Although not too far off - char is the product of burning bones and hooves; it is used to filter some alcohol drinks (some beers/wines/liquor) and some cane sugar (including some brown sugars). Beet sugar is not filtered with it.

Source: http://www.vrg.org/journal/vj97mar/973sugar.htm

The problem is that char is never listed on the package, because it is not actually an ingredient. Also a lot of products that do not use it, don't state so.

Here is a list of some vegan (un)friendly US sugar-making companies; I haven't found a similar resource for Canada or other parts of the world yet.