An initialism is an abbreviation made from the initial (first) letters of a group of words (and pronounced as individual letters), like this:
Sometimes only the more important letters are included:
Here are some more examples:
|ATM||automatic teller machine|
|BA||Bachelor of Arts|
|CEO||Chief Executice Officer|
|DIY||do it yourself|
|NSA||National Security Agency|
|PLC||Public Limited Company|
|PTO||please turn over|
|VAT||value added tax|
|VIP||very important person|
How do we punctuate initialisms? Do we put a full stop/period after each letter?
This is largely a matter of style. Some people prefer the modern approach and use no full stop. Others take a more tradional approach and use a full stop. So CEO and C.E.O. are both acceptable. The important thing is to be consistent.
If the initial letters of the full form are capital letters, then the initialism should also use capital letters (National Security Agency → NSA). If the full form does not require capitals, then the initialism can usually be with or without capitals—it's a matter of style (please turn over → PTO or pto).
Note that some initialisms can also be acronyms. For example, the abbreviation for Value Added Tax (or value added tax) is:
- sometimes written VAT/V.A.T. and pronounced as letters (/vee-ay-tee/)—initialism
- sometimes written VAT/vat and pronounced as a word rhyming with cat—acronym
We usually pronounce initialisms as individual letters—or else we say the full form.
write and say: ATM - BA - CD - CEO - DIY - NSA - PLC - PTO - UN - VAT - VIP