On 24 Feb 2006, "Bart Senior" .@. wrote:

What one-design class features the letters I and C.

International One Design

What features distinguish this class of racing keelboat?

That their long overhangs, comparatively slim bodies, and large-ish
sail plans make them beautiful to look at? That they were designed
primarily by Corneilius Shields in the mid-1930s and that there are
still comparatively large and active fleets?