I am looking at what I perceive to be the same Casio retro digital A168 watch but I find that three sources have differing model numbers on the back. Specifically, the watch is the Casio G-Shock A168WEM- 2D or 2EF or 2VT I believe the 2 designates the color of the face. In this case 2 probably designates blue. After that, what does D or EF or VT mean? Obviously, I suspect they refer to the market in which they are dedicated to w/J or some variation of that meaning JDM. Concerning export markets, I strongly suggest that is what these letters designate. Interestingly, the 3 watches come from 3 markets or geographic regions-----Asia which has the D designation, Europe which has the EF designation, and finally the US which has the VT designation. Who is knowledgable enough to explain the difference since they all appear to be the same watch (but I bet there are some minor (not so obvious variations such as ever so slightly different color). So, please what does D mean? What does EF mean? And, finally, what does VT mean???? I appreciate your interest and help.