§70

Wittgenstein wants to say that there are no clear criteria for exactness that apply in every case. What counts as exact depends on our purposes and the kind of thing that is in question. Perhaps you could say that you've told someone exactly what 'game' means when you've pointed to quite a few games and added a similarity rider and are satisfied that they've understood.

Is it that what counts as exact depends on circumstances or is it that we'll be satisfied with a certain degree of exactness in certain circumstances and want to be more exact in others? (Or both?) - I think both.