Let $\mathscr{A}$ be a locally small category. A functor $X{\colon}\linebreak[0] \mathscr{A}^\op \to \mathbf{Set}$ is representable if $X \cong \h_A$ for some $A \in \mathscr{A}$. A representation of $X$ is a choice of an object $A \in \mathscr{A}$ and an isomorphism between $\h_A$ and $X$.