What do these letters mean on Nikon lenses?

AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED
AF-I NIKKOR 300mm f/2.8D IF-ED

I know that the AF means auto focus, and the VR means vibration reduction, but what do the letters -S, -I, IF, and ED mean? Also after the f number there's either a D or a G, what do these mean?

AF are the older auto-focus lenses that require the camera body to have an internal auto-focus motor
AF-S lenses are the new ultra-high speed auto-focus lenses which have the auto-focus motors in the lenses.
ED is a special optical glass which reduces lens flare and ghosting.
The G version lenses do not have an external aperture control ring.
IF is internal focus meaning that the front element of the lens does not rotate as you focus the lens. This is important if you are using a polarizing filter

Here is a link that should answer questions you have yet to determine.

Http://www.kenrockwell.com/...y-lens.htm" class='ext_link'>http://www.kenrockwell.com/...y-lens.htm

Http://www.kenrockwell.com/nikon/compatibility-lens.htm try that