When providing phone support to one of my clients, this exchange actually took place.
Me: Now type C:Program FilesFilemakerexample.dat
Client: Which key is the backslash?
Me: Did you go to the Command prompt like I instructed you?
Client: Yes.
Me: Do you see the C: on the screen?
Client: Yes. But what key is it?
Me: Can you see your keyboard?
Client: Yes. But which key is it?
Me: You use a lot of different style keyboards there and it can be
located above or below the Enter key.
Client: But which key is it?
Me: Can you see the backslash on the screen? Look for that symbol on
your keyboard.
Client: But which key is it?
Me: I can be there in a few hours.