It would be nice if the server sent the client what height clouds should render at by default. (At login for example.) Servers that have custom world types with sea level above normal look weird having clouds closer to or below the ground. The client could still override the server setting but I think it having the server say what height is appropriate makes sense as it knows the world generation parameters.
I think it's more intuitive to sort case-insensitively, I've been tripped up numerous times by this.