'New Scientist' writer Stanley Newman coined the term “RAS syndrome” in 2001 as a diagnosis for anyone who adds an extra word to the end of common acronyms like “ATM machine” (Automatic Teller Machine machine), making the whole phrase redundant and repetitive. You’ll be surprised how often examples of Repetitive Acronym Syndrome come up.
15 Redundant Words That Make You Sound Ignorant

Don’t say: “PIN number”
“PIN number” translates to Personal Identification Number number. Using these 26 words makes you sound stupid.

Don’t say: “LCD display”
“LCD display” translates to Liquid Crystal Display display.

Don’t say: “PDF format”
“PDF format” translates to Portable Document Format format. Follow these 41 grammar rules to sound smarter.

Don’t say: “ICBM missile”
“ICBM missile” translates to Intercontinental Ballistic Missile missile.

Don’t say: “ISBN number”
“ISBN number” translates to International Standard Book Number number. These are the 11 most hilarious newspaper typos ever printed.

Don’t say: “SAT test”
“SAT test” translates to Scholastic Aptitude Test test.

Don’t say: “GRE exam”
“GRE exam” translates to Graduate Record Examination examination. Here’s why using big words doesn’t make you sound smart.

Don’t say: “VIN number”
“VIN number” translates to Vehicle Identification Number number.

Don’t say: “UPC code”
“UPC code” translates to Universal Product Code code.

Don’t say: “GOP party”
“GOP party” translates to Grand Old party party. These funny autocorrect fails will make you LOL.

Don’t say: “ATM machine”
“ATM machine” translates to Automatic Teller Machine machine.

Don’t say: “CNN news network”
“CNN news network” translates to Cable News Network news network.

Don’t say: “AC current” / “DC current”
“AC current” / “DC current” translates to Alternating Current current / Direct Current current. These are the 10 most annoying phrases in the English language.

Don’t say: “DMZ zone”
“DMZ zone” translates to Demilitarized Zone zone.

Don’t say: “Please RSVP”
“Please RSVP” translates to Please Respond Please (RSVP is short for the French, répondez s’il vous plaît). These are the 11 words and phrases smart people never, ever use.