I do not understand how something can be simultaneously 12 and 18. If there were two speed limit signs, one at 50, and a second at 75 how would you reconcile it?
I understand that one or the other is in error and that both cannot be correct in context. The part has extra margin for higher voltages, but 150% is a bit much, and the application is automotive but low power so 13.5v or even up to 15+ is possible.
I bought it at Radio Shack. It is the standard packaging and has a sticker which I assume is the serial number. Here is a blogpost with a picture - the main difference is that on the back, it says "INPUT VOLTAGE: 7-18V". I checked multiple packages. The UNOs and Megas said 7-12,. The two ADKs both said 7-18v.
https://picasaweb.google.com/lh/photo/Yvy4JiGRfegZuCAdPfzZCNMTjNZETYmyPJy0liipFm0
Their product summary page says 6-18V