I don't work for Titleist, but I can tell you that every 2 years a new version of the ProV1 is released. For each new version the A.I.M. stamp is changed. You are referring to the '07, '09, '11 and '13 models. If I remember correctly, versions prior to '07 do not have the extended arrows around the stamp.

I know this years ProV1 the arrow is a grey color and last years ProV1's have a black arrow.

Thanks for this post. I have been playing Titleist balls for years and didn't realize this marking existed.

You're right.

The '09 version has a skinnier arrow with a dot on either side, and the '07 version has the same arrow without the dot.