Generally speaking these phrases can be classified as pleonasms - more words than required are used to express the concept in question. Interest in this phenomenon has also resulted in these more specific terms: ‘RAP (Redundant Acronym Phrase) phrase’ and ‘RAS (Redundant Acronym Syndrome) syndrome’ - let the self-referential irony not go unnoticed!
Being both curious and empirically-minded, I turned to our corpus, CHIC, to find out more about ‘real life’ manifestations of this phenomenon and was rewarded with ample evidence of acronym-related redundancy.
Examples (beginning with more common cases) include:
- ATM (Automated Teller Machine) machine
- ISBN (International Standard Book Number) number
- LCD (Liquid Crystal Display) display
- DVD (Digital Versatile or Digital Video Disc) disc
- DMA (Dynamic Mechanical Analysis) analysis
- NAFTA (North American Free Trade Agreement) agreement
- IRNA (Islamic Republic News Agency) agency
- JOA (Joint Operating Agreement) agreement
- CD (Compact Disc) disc
The PIN number example is by far the most common. In CHIC, the term 'PIN number' is used 195 times while ‘PIN’ (as a standalone phrase) occurs 160 times. Looking at the way the occurrences are distributed across the different subject areas in the corpus we can see that PIN without 'number' occurs with significantly higher relative frequency in the Applied Science and Technology domain.
This supports the idea that the redundant word is intended to disambiguate or clarify meaning. In scientific or technical writing it is assumed that both writer and reader will be familiar with an acronym’s meaning or stylistic conventions for glossing acronyms will be adhered to. In more general communication, however, a speaker or writer may be unsure of their own or their audience’s familiarity with an acronym’s precise meaning. The seemingly redundant phrase is therefore an attempt, often subconscious, to reinforce intended meaning.
While it’s likely that clarity was the initial motivation for redundant acronyms such as ‘PIN number’, this particular word combination appears to be evolving into a set phrase with the original meaning of the acronym becoming less important. The corpus again provides evidence for this. Of the 195 hits for the corpus query ‘PIN number’, only 52% of cases are of the form ‘PIN number’ while 7% are of the form ‘Pin number’ and 41% of the form ‘pin number’ where the acronym appears to have completely lost its status as such.
This sort of redundancy is generally regarded as stylistically objectionable but as observers and recorders of the language use, we are duty bound to monitor all instances of lexicalisation, even of rule breakers like RAP phrases.