My bro thinks that having "no box gifts" written is a wonderful idea. Especially if your getting married, because like if you buy a house your going to settle down peacefully and buy stuff slowly, instead of if you have a bunch of stuff to put in there the first day....(but i think he thinks that because when he gets married he'll have to get back on the plane...and you can't bring that many gifts on the plane...)
my opinion on the other hand is that you shouldn't write about the gifts...not that anyone DOESN"T give gifts but...don't put unnecessary attention on that...
and the gift registry is a good idea but NO ONE follows it...recently i've seen people have gift registries (wedding and baby shower) and it DIDN'T work out. Nobody went to the gift registry place so the to-be mother had about 10 different types of play sets on her WITHOUT gift receipts.....:(
the only reason "no box gifts" should be used is if your in my bro type of position...
other than that...just don't put anything about gifts...ppl wanna bring something, they will, in whatever way they want to...even if you write something...:)