Acronyms are words created from the first letter or letters of each key word in a sequence and are pronounced as words. Radar (radio detection and ranging) and NOW (National Organization for Women) are two examples. Initialisms are abbreviations formed using the initial, or first, letters of a string of words and are pronounced letter by letter. DVD (digital video disc) and NPR (National Public Radio) are initialisms.
Many grammarians like to quibble about the differences. Not me. I don't care if they are technically acronyms or initialisms. I do care, however, about the common pitfall that stems from their usage. People often find the need to add an unnecessary word after the acronym or initialism. Three examples spring to mind: SAT test, HIV virus and, perhaps the biggest culprit, ATM machine. (The example pictured is from a free playbill I picked up at a University of Connecticut basketball game.) The use of that last one is so widespread, so ingrained, that we think nothing of it. Well, it's time to start thinking, because the redundancy is ridiculous. A = automated. T = teller. M = machine. Using elementary math, we can determine that A+T+M = automated teller machine. Taking our math lesson a step further, A+T+M+machine = automated teller machine machine. It doesn't matter if "ATM machine" sounds right; it's not right. Don't believe me? Try the following paragraph on for size. In it, I will commit sins akin to "ATM machine."
The VIP person — a CEO officer, perhaps — had headphones on, listening to "Proud Mary" by CCR Revival, when he approached the ATM machine at 9 p.m. PST time and punched in his PIN number. He withdrew $200, and at that very moment a bright light appeared in the sky. Was it a UFO object? He wasn't sure. Preoccupied by thoughts of aliens, he failed to notice the SWM male, hopped up on LSD diethylamide, exit a nearby SUV vehicle. Playing out like a dark HBO Office drama, with violence that would put an NFL League game to shame, the SWM male smashed a GPS System device against the back of the victim's head, took his cash and fled. A passing EMT technician performed CPR resuscitation, but by time the ambulance reached the ICU unit, the victim was DOA arrival. Despite DNA acid found at the scene, the murderer has yet to be apprehended. Police believe he may be a student with OCD disorder at nearby USC California, though his identity is TBD determined.
FYI, readers, I'd like to live in a world where the likelihood of acronym/initialism superfluousness is analogous to the possibility of a virgin contracting an STD. (One sentence, two initialisms, zero redundancies.) Let's put an end to "ATM machine" and its ilk. May they RIP peace. Oops!