Wingdings are a series of so-called "dingbat fonts" in Microsoft Word. They display symbols and pictures instead of letters, with each symbol corresponding to a different letter. In 1992, soon after the release of Windows 3.1, a rumor began to circulate alleging that anti-semitic messages had been coded into wingdings. The cause of this rumor was the (true) fact that if you typed the letters NYC using wingdings, you got a skull and crossbones, a star of David, and a thumbs up symbol:
Conspiracy theorists claimed that Microsoft programmers had deliberately designed this into the font as a way of urging people to kill New York City Jews. Microsoft strongly denied these allegations. However, because of the controversy, when Microsoft designed the successor to wingdings in the late 90s, Webdings, they deliberately ensured that a happy message appeared when the letters NYC were typed:
September 11, 2001
The wingdings controversy returned after 9/11, when an email began to circulate claiming that wingdings had predicted the attack on the World Trade Center. The rumor alleged that if you typed Q33NY using wingdings (Q33NY supposedly being the flight number of one of the planes that crashed into the World Trade Center) you would see a picture that looked like a plane flying towards two building towers followed by a skull and crossbones and the star of David.:
In reality, Q33NY was not the flight number of any of the hijacked planes. Their flight numbers were 11 and 175. Q33NY was completely meaningless. It was simply what needed to be typed in wingdings in order to get a plane and two buildings to appear.