Another common instance of this is when dealing with spaces (sets with additional structure); one often abuses notation by using the set itself to denote the space, e.g. a group might be denoted by its set $G$ of elements, rather than by the tuple $(G, e, \cdot, ()^{-1})$ of group structures, or a set-theoretic function by just the mapping $f$, rather than than the triplet $(f,X,Y)$ that includes