| PIN number |
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PIN |
Those who object to “PIN number” on the grounds that the N in “PIN”
stands for “number” in the phrase “personal identification number” are
quite right, but it may be difficult to get people to say anything else.
“PIN” was invented to meet the objection that a “password” consisting of
nothing but numbers is not a word. Pronouncing each letter of the
acronym as “P-I-N” blunts its efficiency. Saying just “PIN” reminds us
of another common English word, though few people are likely to think
when they are told to “enter PIN” that they should shove a steel pin
into the terminal they are operating. In writing, anyway,“PIN” is
unambiguous and is better used without the redundant “number.”
The same goes for “VIN number”; “VIN” stands for “Vehicle Identification
Number.” And “UPC code” is redundant because “UPC”stands for “Universal
Product Code.”
Similarly, “ISBN number” would logically mean “International Standard Book Number number.” It’s fine to say just “ISBN,” and that’s what most professionals in the book trade do.
