Just to know..
Hi Wbeem,
of course, several lenses made in the '90s (D type, and some older) have this kind of red switch, since with all the latest nikon cameras you set aperture from the two dials (the rear one if you are in mode P, the front one if you are in A or M) but they give you the ability to use newer lenses on older cameras where you had necessarily the needing to set aperture via the lens ring. Every Nikon (and non nikon lens) on a new Nikon Camera must be ALWAYS locked with that switch, otherwise you will get an FEE error.
No problem for newer G-type lenses since they haven't any aperture ring any longer.
All the best