=over 4
+=item MEMCACHED_BEHAVIOR_USE_UDP
+
+Causes libmemcached(3) to use the UDP transport when communicating
+with a memcached server. Not all I/O operations are supported
+when this behavior is enababled. The following operations will return
+C<MEMCACHED_NOT_SUPPORTED> when executed with the MEMCACHED_BEHAVIOR_USE_UDP
+enabled: memcached_version(), memcached_stat(), memcached_get(),
+memcached_get_by_key(), memcached_mget(), memcached_mget_by_key(),
+memcached_fetch(), memcached_fetch_result(), memcached_value_fetch().
+
+All other operations are supported but are executed in a 'fire-and-forget'
+mode, in which once the client has executed the operation, no attempt
+will be made to ensure the operation has been received and acted on by the
+server.
+
+libmemcached(3) does not allow TCP and UDP servers to be shared within
+the same libmemached(3) client 'instance'. An attempt to add a TCP server
+when this behavior is enabled will result in a C<MEMCACHED_INVALID_HOST_PROTOCOL>,
+as will attempting to add a UDP server when this behavior has not been enabled.
+
=item MEMCACHED_BEHAVIOR_NO_BLOCK
Causes libmemcached(3) to use asychronous IO. This is the fastest transport
this value to high, may cause libmemcached to deadlock (trying to send
data, but the send will block because the input buffer in the kernel is full).
+=item MEMCACHED_BEHAVIOR_NOREPLY
+
+Set this value to specify that you really don't care about the result
+from your storage commands (set, add, replace, append, prepend).
+
=back
=head1 RETURN