Just curious, why did u need to know that and what does it mean?
An SLR camera is capable of having different size lens attached to it. The "FD" that I was talking about is the way that a lens attaches to the camera. I have lots of FD Lens and would be able to utilize them if they fit the camera. However, the EOS 650 uses FE Lens and the ones that I have are not compatible.
Glad you got it sold. Thanks.