Nikon lens naming [duplicate]

Question

Possible Duplicate:
What does all those parts in a lens name mean?

I'm thinking about buying myself a new lens for my Nikon and I have a question about the naming conventions Nikon uses for its lenses. Some of the things I have figured out on my own but looking at the following few lens names

• AF Nikkor 14mm f/2,8D ED
• AF-S Nikkor 35mm f/1,8G DX
• AF Nikkor 180mm f/2,8 D ED-IF
• AF-S DX Nikkor 16-85mm f/3,5-5,6G ED VR

Ok I know some of those

• ##mm is the focal length
• f/#,# is the max aperture
• DX is to mark the lens as not full frame
• VR is Vibration Reduction

But what is the difference between G and D and what are ED and ED-IF?

Answer 1

G is for without aperture ring. If you look at the G lens and non-G lens, the non-G lens will still have the aperture ring, allowing you to use it with older non-dual-dial (front and back) camera by setting the aperture via the ring instead of the front dial.

D designated for the "distance" information communicated by the lens to the camera. Obviously, this is crucial for AF. Some older lenses that are still manual won't have this, but some do. Newer lens all have this. If you have a "IF" or "G" lens, it assumes the "D".

IF means "internal focus". So when focusing (manually or auto), it won't rotate the front element of the lens, it will only adjust the internal lens components to achieve focus. All "G" lens is "IF"

ED designated the presence of "ED" (stands for "Extra-low Dispersion") glass/element in your lens. "ED-IF" is a combination of "ED" and "IF".