-memcached_callback_get() return the function or structure that was provided.
-Upon error, nothing is set, null is returned, and the memcached_return_t
-argument is set to MEMCACHED_FAILURE.
+\fI\%memcached_callback_get()\fP return the function or structure that was
+provided. Upon error, nothing is set, null is returned, and the
+\fBmemcached_return_t\fP argument is set to \fBMEMCACHED_FAILURE\fP.