Restrictive, I would say, since you are restricting the group "playlists" to "only those that are albums" . Now, if that makes little sense to you, please accept my apologies, my mother tongue is Italian, so I am just almost "guessing" based on my highschool books, or, actually, what I remember of those! Just trying to give my contribution because I have always been curious about languages and I would like to get a proper answer too And btw, sorry for the off topic... ehm...