When I know the connection already and interested in job what's the point of hiding it. I can always ask the connection that they have any opening for me. May be I am missing something here or the page is not explaining it enough. Good luck!
Thanks for the comment. It is for some cases, where you don't want to take the first step because of previous history with this person, or due to your current position. Or personality and cultural nuances may push some people to shy away to make the first step. It all depends on your relation with your connections. Let's see if it will make sense for some people.