A pseudo-acronym (or empty acronym) is an apparent acronym or other abbreviation which doesn't stand for anything, or cannot be officially expanded to some meaning. An orphan acronym is a pseudo-acronym that was once a true acronym or initialism. For instance:

• AARP, which originally stood for the American Association of Retired Persons, but was changed in 1999 and no longer stands for anything.
• AIGA, which used to stand for American Institute of Graphic Arts, now does not stand for anything, the organization having broadened its focus.
• AIESEC, formerly the abbreviation for "Association internationale des étudiants en sciences économiques et commerciales", now does not stand for anything, the organization having broadened its members profile.
• AT&T, which used to stand for American Telephone and Telegraph, no longer deals in telegraph and never goes by the expanded version.
• CM(as part of professional wrestler's ringname CM Punk), which used to stand for various things, such as Cookie Monster and Chick Magnet, but then claimed it didnt stand for anything.
• D-A-D, a band which was originally named Disneyland After Dark but changed the name after a threatening lawsuit from The Walt Disney Company. The new name stands for nothing.
• DCI, which used to stand for Duelists' Convocation International, is now simply the DCI.
• ECHL, which used to stand for East Coast Hockey League, now does not stand for anything; expansion into Alaska, British Columbia and California effectively made its "East Coast" title incorrect.
• FFA, which used to stand for Future Farmers of America, now does not stand for anything, the National FFA Organization having broadened its focus.
• The SAS System, which originally stood for the Statistical Analysis System programming language, has now outgrown its acronym and officially stands for nothing.
• SK Gaming, in which "SK" originally stood for "Schroet Kommando". It now does not stand for anything.
• UNISON, Britain's largest trade union, looks like an acronym, particularly since the names of many British trade unions are acronyms, but it is not.
• The I.O. Theatre used to stand for Improv Olympic. After a trademark dispute with the Olympics, the theatre agreed to call itself IO, which would officially stand for nothing.
• ISO, a world-wide standards organization, is formally named the "International Organization for Standardization" in English and "Organisation internationale de normalisation" in French. The term ISO was never an acronym; it's simply a Greek word. ISO are silent regarding their choice to consistently spell the word in all capitals — a practice which causes many English speakers to mistakenly believe that the term is an acronym or initialism for "International Standards Organization".
• NASDAQ was originally an acronym for National Association of Securities Dealers Automated Quotations.
• xkcd, the title of a webcomic created by Randall Munroe, stands for nothing and never has.
• The short-lived XFL purportedly stood for Xtreme Football League, but league officials denied it. (Coincidentally, the XFL's only champions were the Los Angeles Xtreme.)