That sign which it creates I call the interpretant of the first sign. The sign stands for something, its object. Because the indexical sign is understood to be connected to the real object, it is capable of making that object conceptually present. A symbol is an arbitrary, conventional and generally unmotivated relation of sign and object. If this seems a little confusing, it is.
Clues are something completely different, yet fundamentally the same.
The problem is that a clue can only be a clue if we know what it is that we are looking for. So, we are left kind of high and dry if we want to critique the story that's told to us, unless we can back off of the thing and talk about the construction of narrative as such, how a successful narrative can be made to work. Our job as readers is to locate the one, and our job as writers is to develop the other. I hope this helps a little. Theories of Representation and Difference.