FANTL is an abbreviation for the For All Nails Time Line, an alternate history based upon Robert Sobel's For Want of a Nail . . . but extended (and occasionally "corrected") by the authors in the For All Nails project.
In general articles on this wiki describe only the history set out in For Want of a Nail . . ., referring to the extensions of the FANTL where useful. For example, the historian Joan Kahn has a page listing her works as referred to by Sobel, and that page mentions that she is a major character in For All Nails as well.