Funny | Random | Wordplay | Pet Peeves

Does It Annoy You When People Expand One of the Letters in an Acronym?

There’s a name for it: RAS syndrome

Alan AJ
2 min readNov 28, 2023


An AI-generated ATM with a sign above that says “ATM Machine”. On the screen, it says “LCD DISPLAY”.
Two examples of RAS syndrome. Image created by the author using Image Creator from Microsoft Bing. The text was modified slightly using Affinity Photo

When I worked for an electronics company, it annoyed me when colleagues said things like ‘LCD display’ or ‘ISBN number’.

When expanded, all these terms repeat themselves:

  • LCD display — Liquid Crystal Display display
  • PCB board — Printed Circuit Board board
  • ISBN number — International Standard Book Number number
  • UPC code — Universal Product Code code
  • USB bus — Universal Serial Bus bus

Someone came up with a name for this

  • RAS syndrome — Redundant Acronym Syndrome syndrome

According to Wikipedia, the term RAS syndrome was coined in 2001 in a light-hearted column in New Scientist.

More examples

It’s surprisingly common! And in some cases (e.g. ETA), it’s not the last letter that gets repeated.

  • ATM machine — Automated Teller Machine machine
  • CMS system — Content Management System system
  • DVI interface — Digital Visual Interface interface
  • ETA time — Estimated Time of Arrival time
  • GPS system — Global Positioning System system
  • PIN number — Personal Identification Number number
  • PDF format — Portable Document Format format
  • SAT test — Standard Assessment Test test
    (or Scholastic Assessment Test test)
  • VPN network — Virtual Private Network network

Some acronyms might trick you

On rare occasions, it looks like you’ve spotted another example of RAS syndrome. However, upon closer inspection, there is no redundancy.

They are harder to think of, but here are two examples.

  • MOT test — Ministry of Transport test
    You might assume the T in MOT means test, but it does not. Therefore, this is not an example of RAS syndrome. But it still feels like it is!
  • SOS signal — Save our Souls signal
    The last S does not stand for signal, so it is not RAS syndrome.

Does it annoy you when people say things like ‘ATM machine’ and ‘ISBN number’, or do you not mind?

Thank you for reading
Alan 💛



Alan AJ

Random life stories, opinions, and a dry sense of humour. A 55-year-old former electronics engineer and programmer in England. Previously 'Autistic Widower'.