Five Acronyms

What do the following acronyms have in common?

  • LCD display
  • ATM machine
  • PDF format
  • ISBN number
  • HIV virus

All five are examples of the RAS syndrome (Redundant Acronym Syndrome syndrome) in which the last word of the acronym is repeated.

  • Liquid-Crystal Display display
  • Automated Teller Machine machine
  • Portable Document Format format
  • International Standard Book Number number
  • Human Immunodeficiency Virus virus