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.
Question authority
"Question authority" is a popular slogan often used on bumper stickers, T-shirts and as graffiti. The slogan was popularized by controversial psychologist Timothy Leary, although some people have suggested that the idea behind the slogan can be traced back to the ancient Greek philosopher Socrates. One of the most influential icons in the counterculture movement which formed in the late 1960s out of opposition to the Vietnam War's escalation, Leary gained influence among much of the youth by advocating the use of LSD – which was criminalized in the United States in 1966 – as a way to escape from the burdens of society. Following the Watergate Scandal, which resulted in the resignation of US President Richard Nixon and the conviction of several officials in the Nixon administration, the slogan became arguably the most accepted form of ideology among baby boomers.