... are often all that's needed to identify a person, a place, a thing, a concept... for example:
ABC... ATM... BLT... CBS... CEO... DUI... FBI... GTO... IBM... KGB... LOL... MGM... MPG... NBC...
NFL... POW... RBI... RPM... SOS... TKO... TNT... UPS... WTF... you get the idea... and in the chip world:

Got any "3 letter" items from your collection you'd like to share?