In Darril Gibson's Sec+ study guide, p.140 under Encryption protocols ==> SSH

"[...] SSH can also encrypt TCP wrappers, a type of of access control list used [...]"

Does anybody know what he means by that? I'm well aware you can use TCP wrappers to limit who can connect to the service, but clearly he's saying something completely different here. I did a quick Google search on the subject and the only thing that comes up from several different websites is how to use TCP wrappers to limit access to one service or another using /etc/hosts.allow and /etc/hosts.deny, nothing about using TCP wrappers and SSH to encrypt a service working otherwise as plain text.