There's nothing amusing about illiteracy.
But maybe you remember how, in certain old movies and TV Westerns, a grizzled old-timer would be encouraged to make his "mark" on some document in lieu of producing a formal signature.
Then the old guy would dutifully scratch an "X" on the paper.
I suppose those scenes might have had some loose basis in historical reality.
But here's what I'm wondering. If you were going to make your mark on a document instead of writing your name, what sort of symbol would you draw?