D Meson Decays into $\phi$, $\eta$ and $\eta'$

We report on inclusive and exclusive decays of charmed mesons into particles that have a large content of $s\overline{s}$ quarks, namely the $\phi$, $\eta$ and $\eta'$. Data taken with the CLEO detector in the energy region where correlated $D\overline{D}$ pairs are produced are used, where one $D$ meson is fully reconstructed and then the properties of the other $D$ are examined. These measurements are particularly useful for ascertaining the properties of $B$ meson decays.