PIN Number (PIN=Personal Identification Number), no need to repeat number

RSVP please (RSVP=Answer please in French), no need to say please again


  • Or my pet peeve: JITC compiler.
    – Hot Licks
    Jan 15, 2018 at 23:41
  • 2
    Answered at "PIN Number" — why do we say it? (the special type of redundancy known as RAS Syndrome: Paul Rein's answer). Jan 15, 2018 at 23:42
  • @Tonepoet - Shouldn't the note read "Possible RAS (Redundant Answer Syndrome) syndrome"?
    – Hot Licks
    Jan 16, 2018 at 0:00

1 Answer 1


It's been given the ironic and self-referential label RAS syndrome, where RAS stands for Redundant Acronym Syndrome¹.

From Wikipedia:

RAS syndrome

RAS syndrome (where "RAS" stands for "redundant acronym syndrome", making the phrase "RAS syndrome" humorously self-referential) refers to the use of one or more of the words that make up an acronym or other initialism in conjunction with the abbreviated form, thus in effect repeating one or more words.

Two common examples are "PIN (or VIN) number" (the "N" in PIN and VIN stands for "number") and "ATM machine" (the "M" in ATM stands for "machine"). The term RAS syndrome was coined in 2001 by New Scientist.

The more general term in linguistics is the unsurprising redundancy.

¹ Thus RAS syndrome, spelled out, is redundant acronym syndrome syndrome, just as PIN number spelled out is personal identification number number.

  • Does ELU really need two answers giving 'RAS Syndrome'? Jan 16, 2018 at 0:07
  • @EdwinAshworth I answered before anyone suggested it was a dupe. You can feel free to close the question as a dupe. I won't mind.
    – Dan Bron
    Jan 16, 2018 at 0:08

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