The C tells only that there ist something extra with the saw. That could be a heating for handles and carburator oder something else like an M-Tronic. Not more, not less.
My 241 is an C-M VW for example. And my 261 is an C only with only a spring in the handle of the rope for better pulling experience, no M-tronic and no heatings or everything else.
But both carry a C on the left side plate.