Hrvoje> It would be very wasteful, I think. It's wasteful only if automatic and user recognition of coding systems are nearly 100% accurate. Otherwise it would be really nice to be able to reliably tell Mule to efficiently convert from one to another. We should be careful about the semantics of "OBJECT in coding system". If we got the correct input coding system, then changing the output coding system of the current object is trivial. It's the same as changing a face. (What this causes redisplay to do is non-trivial; but resetting the specifier is an assignment: trivial.) If we screwed up the input coding system then we need to invert the input mapping and apply the new input mapping to the inverse image of the current OBJECT, an order-n operation.