Originally Posted by
Sheldon Brown
The so-called "road" derailers are not available with long (SGS) cages. They are available with short (SS) and medium (GS) cages only.
Shimano's literature sometimes confuses things by calling the medium cages "long."
Fair enough, but I think you see what I mean, esp. per Shimano literature. It seems many LBS crews have succumbed to this terminology, as well...i.e. anything that's not "short" is "long".