About reliability of secure pipes in the documentation

I was reading the Jxta Programming Guide and the JXTA specifications 
looking for information about reliability of unicast secure pipes.

The JxtaProgGuide states at page 15 that a secure unicast pipe is a 
type of point-to-point pipe that provides a secure, and reliable 
communication channel.

The JXTA Spec in the chapter 1.4.1 (Pipe Advertisement) instead say:

JxtaUnicastSecure: may not arrive at destination, may be delivered more 
than once to the same destination, may arrive in different order, but 
is encripted using TLS.

So, are JxtaUnicastSecure pipes reliable or not ?