As a follow up of my question What does the 'F' button and '2' button do (materials tab)?, I have another question:
When I added an object mesh and applied a material, and I added another mesh, not duplicate but with ShiftA, and choose this same material than it is added as a new user (checked by press the 'F'-button and look at the number next to it).
When I duplicate linked an object by AltD their material data are linked, but this duplicated linked object mesh is not added as a new user (checked by press the 'F'-button and look at the number next to it)
But when I change the viewport color of the material then the added objects meshes (with ShiftA) and the duplicate linked object meshes (AltD) do change their viewport color. So are material from added objects linked different then the material from duplicate linked objects?