Notification received that someone added me to a list on Facebook?

[Lis C]

I received a notification that said: [Name of friend] added you to his [name of list]. I've never seen this before. Do people know when you add them to a list? I keep reading the answer is no, but now I'm starting to see this.

I tried searching for an answer on Facebook itself to no avail. Thanks!
Thanks, Jonathan.

I thought friends were not supposed to know if you put them on a list, etc. I can't see a privacy setting to prevent someone from seeing this. Any further info??
I see...so by "list" they actually mean the new groups. That makes sense!

[Jonathan]

On Facebook, you can create friend lists to sort your friends as you please.
That notification probably just lets you know which list your friend has put you in.

[debijs]

~~Any of your friends can form groups to organize their friends. Like "family" "gaming friends" " close friends" whatever, to that affect. So you have just been added to a list by one of your friends who is organizing their friends list.~~