can't cleanly log out of ssh

[jc at trillian.mit.edu (John Chambers)]

Rajiv Aaron Manglani wrote:
| >> try listing open ports:
| >> in the ssh session press: ret ret ~ #
| > Ooo - that's slick.  I'm going to have to remember that one.
|
| there are a few more of these. man ssh and look for 'Escape Characters'

Yeah, but there's not much explanation.  When I use ~# the result is:

: ~#
The following connections are open:
  #0 client-session (t4 r0 i0/0 o0/0 fd 4/5)

But I don't see any clues in the man page about that parenthized stuff.
Anyone have any idea what it's trying to tell me?