-On success that value will be C<MEMCACHED_SUCCESS>.
-Use memcached_strerror() to translate this value to a printable string.
+On success that value will be C<MEMCACHED_SUCCESS>. If called with the
+C<MEMCACHED_BEHAVIOR_USE_UDP> behavior set, the value C<MEMCACHED_NOT_SUPPORTED>
+will be returned. Use memcached_strerror() to translate this value to
+a printable string.