Well I don't have a lot of spare time on my hands between working for the man 50-60 hours a week + other business. So here is what I got.
On any given unit you go to the system info tab(where it shows the serial number and console ID kernel version etc)
Then press any other button 4 times. I started with the D-pad Up, Down, Left, Right then the X,Y,A,B
I've not had any units yet that were triggers..but i suppose its possible that out of 10 units none of them were that.
Really you don't have to hit the same button 4 times..as long as the last button press is the one tied to your console.
Where they gave me the parental unlock code YARY all I had to do it press Y as the last button and it would work.
Well hopefully this is new information and I actually figured out something new...either that or I wasted 2 hours of my time trying to figure something out that is already known. LOL