Can anyone please explain what ghost links/hints in Fontlab are used for? Thanks!
These are hints that are used to control vertical alignment of features that do not involve horizontal stems. The obvious example would be the top and bottom of a sans serif letter I. There is no serif to function as a horizontal stem, and hence nothing to which to link a standard stem hint. Ghost hints are used here to attach the top and bottom of the letter to vertical alignment (blue) zones.
Got it, thank you John!