The current DFDL spec dates from Sept 2014. There have been numerous corrections and clarifications added to it.
Those are listed in a separate errata document; however, a new revised version of the specification is in preparation by the Open Grid Forum DFDL Workgroup, which has all the errata folded into it. This is easier to use and has change-tracking so the changes from the Sept 2014 revision are highlighted. You'll find a link to this preliminary version here: https://opengridforum.github.io/DFDL Keep in mind this is a work-in-progress and will change. This homepage link will remain live, but the specific document link you find there will break when new revisions come out.
