Question mark
The rhetorical question mark or percontation point was invented by Henry Denham in the 1580s and was used at the end of a rhetorical question; however, its use died out in the 17th century. It was later revived in modern-day society by Matt DiRoberto. It was the reverse of an ordinary question mark, so that instead of the main opening pointing back into the sentence, it opened away from it. This character can be represented using the reversed question mark (⸮) found in Unicode as U+2E2E. The percontation point is analogous to the irony mark, but those are even more rarely seen.
Gregory Edwards
"The question mark might serve as an entry point to the 32-year-old artist's ongoing interest in the push and pull between abstraction and representation, the open-ended sense of play in his wild, often ostentatious patterning and his rigid structural control, and flat, thinly applied surfaces. After all, a question mark added to any last word turns the work of interpretation onto the audience."