It seems to me the title usually reflects something on the island and in the flashbacks. Sun's baby's date of conception was the obvious one, (plus she visited with two Doc's). The off island meaning would have to do with the questionable date of Jin's conception.
DOC often means Department of Corrections, but I don't know what that means in this episode, if anything.
the word is also short for Documentation, yet I don't see how this relates either.
DOC is also an LSD-related drud called DesOxyChloro
Jim Jones from the People's Temple was originally part of the midwestern Disciples of Christ aka DOC and that is a little Dharma-ish, but not seriously.
Obviously it's short for doctor (and thus the title of the Billy Ray Cyrus TV show), yet I don't see how this relates to this episode other than the Doc and Sawyer represent two halves of Billy Ray Cyrus as Doc.
I think you're reading too much into it. The newspaper has been explained as a prop error. DOC means date of conception and is a common term used by medical practitioners. I do personally believe there are diverging timelines involved but I don't think these minor things are evidence of it.
the whole time I was thinking - Dead On Conception, cause on the island the mother and child are basically dead as soon as there is conception... which is such an oxymoron... or at least it encompasses both "the beginning and the end", for the moment of the creation of new life is also the moment death begins, of course this is reality, that the moment we are born we are moving towards death... anyhoo