$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
6.11
\begin{equation} \begin{gathered}\label{equation:localization-essentially-small} \xymatrix { \operatorname{\mathcal{C}}\ar [r]^{u} \ar [d]^{F} & \overline{\operatorname{\mathcal{C}}} \ar [d]^{\overline{F}} \\ \operatorname{\mathcal{D}}\ar [r]^{v} & \overline{\operatorname{\mathcal{D}}} } \end{gathered} \end{equation}