I'm assuming you mean what kind of formula to use or whatnot, since it seems that these extra Verts are the ones for texturing; They're not used on any polygons, and are always located at the same coordinates as at least one other Vert that
is used for a Poly. Further graphical example;
I connected and filled in those spare Verts and that's what you get. Orange is where the Eyes are, and blue is where the Mouth is, no?
For Rufus' head, they're currently labeled as Vertices 108-122. On *all* of the models, these spare Verts will be the last ones listed, and have 255-255-255 color values; I don't think *any* sprite has actual verts with maxed out colors like that. I just looked at the Nurse's head, and her white uniform is only 230-230-230. Rufus' trenchcoat is only 204-204-204. Hojo's lab coat is only 179-179-179.