Examples from the Web for xyz
LACMA shows three of the photographer's early portfolios, XYZ.Robert Mapplethorpe in Los Angeles: Exhibitions at the Getty and LACMA|Isabel Wilkinson|November 5, 2012|DAILY BEAST
"Drill students at XYZ high school until they can correctly answer the questions on ABC standardized test" is a task.
The deal is that Scoble invests in XYZ company, and he makes sure they get a lot of press.Ethical or Not, Silicon Valley Bloggers Hit Up VCs for Angel Funds|Dan Lyons|February 22, 2012|DAILY BEAST
But there's one thing I can do, fellows, from abc up to xyz, and that's write.Dawn O'Hara, The Girl Who Laughed|Edna Ferber
Similarly, x3, xyz are said to be of three dimensions, and the meaning is extended to cover the product of any number of letters.The New Gresham Encyclopedia|Various