The only "required" sticker is the emissions control sticker seen in the picture above. I would contact Ford for the sticker if you really want it.
Here is the CFR reference:
The ECS message happened to me before shortly after I bought my Powerboost, I was driving from MN to ND and filled up with E10 as opposed to "normal" fuel E15 in MN (88 octane). I was told this was a normal message due to fuel changes and that it would go away eventually. The dealer did zero out...
Guys, guys.....If calculus and thermodynamic engineering has taught me anything, the equation you are looking for is: WQH=1−TCTH.
However, gasoline is not an IDEAL gas, there are thermodynamic failures in efficiency with any man made gas. When you enter ethanol in the mix, it gets even worse...
I've only used 87 in my Powerboost. I realize that the manual recommends 91 octane, but I have found no detrimental effects with using 87. Although in MN, ethanol is added and required, so YMMV, literally.