Beside the point? Punctuation is dead, long live punctuation.

Frustrated by the misunderstandings arising from a failure to catch tone in writing, the English printer Henry Denham invented a mark denoting sarcasm. Denham offered his sign in 1575. A mirrored question mark, he hoped, would flag up a rhetorical question, making it easier to get the drift of the writer’s intention. But it never caught on.