The correct terms are: Machine Doubling, MD or MDD (what your coin shows) and Doubled Die Obverse, DDO. I am not at all trying to be difficult. I just see a lot people buying and selling stuff on eBay that is called "Double Date," or "Doubled Date" which are not numismatic terms and could mean one of many different phenomena...
Does it look scooted, pushed or pulled, is it Does it look scooted, pushed or pulled, is it flat and shelve like, does it look like a conituation of the original number, letter or date, does it look "slid" over? These are the questions you need to ask when searching.
