Marking and DFing are really the same thing
No they are not.
If you are DFd, other JW's can be "punished" (threatened with being DFd) for associating with you. If you're "marked" most people won't even remember the talk about it and only the Ricky Righteous crowd will shun you (and those that WANT to shun you). Your "friends" (real ones) can ignore the BS without serious consequences.