Received this notification when accepting a Facebook friend request...?

[Sasha]

I am going on this small program over the summer, and we have a Facebook group were we discuss the program and meet eachother; most of us are all Facebook friends. When a person from the group friended me, I got this notification when I clicked to confirm them as a friend that asked if I knew them personally. Why did it ask me that and has anyone else been asked that?
Thanks!
No, it wasn't the notification that always pops up every time you friend someone. This was a different one that only came up that one time I confirmed a request.
It also said that the person wouldn't see my response.

[akapbcup]

That always happens you can either choose to list how you know them, or you can skip it. If you choose to answer, your friend will have to confirm how you know one another before it will show up officially. I usually just skip the question.

[Samantha]

Yeah, that happens to me on occassion and I often have wondered the same thing. I've come to just assume, though, that it's either because the person is new to Facebook and they need to know that the person is on there not just to make online friends; or because someone has said that this person is not a part of the Network they have said they're in. Other than those small ideas, I have no clue!